Category Archives: Air Racing and Records

piaggio-pegna_pc7

Piaggio P.7 / Piaggio-Pegna Pc 7 Schneider Racer

By William Pearce

Giovanni Pegna was an Italian aeronautical engineer who started to design racing seaplanes and other aircraft in the early 1920s. Partnering with Count Giovanni Bonmartini, the pair formed Pegna-Bonmartini in 1922 to bring some of Pegna’s aircraft designs to life. Pegna was particularly interested in designing a racing seaplane for the Schneider Trophy Contest. Pegna-Bonmartini was short lived, as it was bought out by Piaggio & C. SpA (Piaggio) in 1923, when the latter company decided to start designing its own aircraft. Pegna was appointed head aircraft designer for Piaggio.

Pegna-Pc-racing-seaplanes-2

Giovanni Pegna’s previous racing seaplane designs. The engine and propeller of the Pc 1 pivoted up to clear the water for takeoff, landing, and while operating on the water’s surface. The Pc 2 and Pc 3 were fairly conventional designs but were advanced for their 1923 time period. The Pc 4 had tandem engines in a push/pull configuration and a single, central float. Wing floats would have been incorporated into the design. The Pc 5 and Pc 6 both used a retractable hull that was extended for takeoff and landing. The Pc 6 also had tandem engines in a push/pull configuration.

Pegna’s racing seaplane designs focused on minimizing the aircraft’s frontal area. Some of the designs used floats, while others incorporated a flying boat hull. Construction of the Pc 3 was started by Piaggio in 1923. The “Pc” in the aircraft’s designation stood for Pegna Corsa (Race), and this aircraft most likely carried the Piaggio designation P.5. The Pc 3 was a fairly conventional, single-engine monoplane utilizing two floats, but the aircraft was never finished.

Pegna-Pc-7-Drawing

The Schneider Trophy Contest inspired a number of extraordinary designs, but the Piaggio P.7 / Pegna-Piaggio Pc.7 was the most radical to be built. Its hydrovanes were much smaller and lighter than floats, offering the aircraft a distinct advantage if it could get airborne. Note the water rudder behind the water propeller.

In 1927, Pegna was asked by the Ministero dell’Aeronautica (Italian Air Ministry) to design a racing seaplane for the 1929 Schneider Trophy Contest. After studying three designs (Pc 4 through Pc 6), Pegna became increasingly focused on utilizing a central float that would be extended to support the aircraft on water and retracted while the aircraft was in the air. However, the complexity and estimated weight of the float and its retraction mechanism, combined with the unknown aerodynamic forces during retraction and extension, made the design impractical. Pegna returned to the drawing board and, aided by Giuseppe Gabrielli, designed the Pc 7, which was also known as the Piaggio P.7. On 24 March 1928, the Italian Air Ministry ordered two examples of the P.7 and assigned them serial numbers (Matricola Militare) MM126 and MM127.

After experiments in a water tank, Pegna finalized the aircraft’s design. The Piaggio P.7 (Piaggio-Pegna Pc 7) had a watertight fuselage that sat in the water up to the shoulder-mounted wings when the aircraft was at rest. A two-blade propeller at the front of the aircraft was just above the waterline. The engine was located just forward of the wing and drove the propeller via a shaft. A second shaft extended behind the engine to a water propeller positioned in a skeg under the tail. Clutches on both shafts allowed the front propeller or the water propeller to be decoupled from the engine. When the front propeller was decoupled, it would come to rest in a horizontal position. For takeoff, the engine would power the water propeller with the front propeller stationary. As the aircraft gained speed, the front would rise about 10 degrees out of the water by the hydrodynamic forces imparted on two hydrovanes extending below the fuselage and by a third hydrovane located in front of the water propeller. With the front propeller clear of the water, engine power was diverted from the water propeller to the front air propeller. The front propeller would continue the aircraft’s acceleration until enough speed was gained to lift off from the water’s surface.

Piaggio-Penga-Pc-7-drawing

A view of the P.7’s internal layout. A and B are the drive shaft clutches. C is the lever that engages and disengages the air propeller; when disengaged, it locks the propeller in a horizontal position and closes the main carburetor inlets. D is the lever that engages and disengages the water propeller; when disengaged, it feathers the water propeller. E is not recorded, but it appears to be a bulkhead and support for the propeller shaft. F is a rubber diaphragm operated by the air propeller lever that seals the propeller shaft when the air propeller was disengaged.

The P.7’s airframe was made mostly of wood with some metal components. The aircraft was skinned with two layers of plywood with a waterproof fabric sandwiched between the layers. Two watertight compartments were sealed into the fuselage, and the vertical and horizontal stabilizers were watertight. A single fuel tank was positioned in the fuselage under the wing and between the engine and cockpit. The one-piece wing had three main spars and was mounted atop the fuselage. Two legs extended below the fuselage, and each supported a planing surface. The planing surfaces, including the one on the tail, were inclined approximately three degrees compared to the aircraft while in level flight. The relative angle would increase as the aircraft was landed with a slight tail-down configuration. A water rudder extended below the fuselage directly under the aircraft’s tail. The movement of the water rudder and normal rudder were linked.

Piaggio-Penga-Pc-7-construction

The nearly complete P.7 without its engine or hydrovanes. The original carburetor inlets are visible on the side of the aircraft. Note the pipes for the surface radiators on the wings.

Originally, the P.7 was to be powered by a 1,000 hp (746 kW) FIAT AS.5 V-12 engine. For reasons that have not been found, the engine was switched to an Isotta Fraschini Asso 500 V-12 that produced 800 hp (597 kW) at 2,600 rpm. Isotta Fraschini fully supported the P.7 project, and Giustino Cattaneo, the Asso 500’s designer, redesigned the engine with a rear drive for the water propeller. In addition, new cylinder heads were designed with the exhaust ports on the inner, Vee side of the engine. As originally designed, the Asso 500 had intake and exhaust ports on the outer sides of the engine. Having the open exhaust ports on the side of the fuselage would lead to water intrusion when the aircraft was at rest on the surface. Relocating the exhaust ports to vent out the top of the fuselage resolved this issue. The cylinder heads were most likely the same or very similar to those that Cattaneo had designed for the Savoia-Marchetti S.65 Schneider racer. Cattaneo and Isotta Fraschini also designed at least some of the P.7’s drive systems. Surface radiators on the wings cooled the engine’s water coolant, and engine oil was cooled by a surface radiator on the sides and bottom of the aircraft’s nose.

The cockpit was situated low in the aircraft’s fuselage and between the wing’s trailing edge and the tail. Two levers on the left side of the cockpit controlled the engine’s output to the air and water propellers. One lever engaged and disengaged the air propeller. When engaged, the main carburetor inlets at the front of the aircraft were automatically opened. When disengaged, the carburetor inlets were closed, a rubber seal was pressed against the front of the propeller shaft, and the propeller was slowed and subsequently locked in a horizontal position. The carburetor inlets were originally located on the sides of the aircraft by the engine but were moved to above the nose. When the carburetor inlets were closed, the engine drew in air from the cockpit. When the water propeller’s lever was disengaged, the blades were feathered to offer as little aerodynamic resistance as possible.

piaggio-pegna_pc7

The completed P.7 supported by a hoist illustrates the aircraft’s sleek design. The pilot sat quite far aft, and landings would have been a challenge.

Six air propellers were ordered for testing on the P.7. They varied in diameter and profile. Three were made from steel with a ground-adjustable pitch, and the other three were made from duralumin, and each had a different fixed pitch. One of the steel air propellers was designed by Pegna. Originally, the adjustable-pitch water propeller was made from duralumin components, but testing resulted in a switch to a steel hub with duralumin blades. The Piaggio P.7 had a 22 ft 2 in (6.76 m) wingspan, was 29 ft 1 in (8.86 m) long, and was 8 ft (2.45 m) tall. It had a maximum speed of 373 mph (600 km/h) and a landing speed of 103 mph (165 km/h). The aircraft weighed 3,122 lb (1,416 kg) empty and 3,717 lb (1,686 kg) fully loaded.

The design of the complex and unique aircraft delayed its completion. It appears that the first aircraft, MM126, was completed and sent to Desenzano before the Schneider Trophy Contest was held in September 1929, but there was not enough time to test the P.7 before the race. Both P.7 aircraft were finished by late October 1929, which is when testing began. Most pilots of the Italian Reparto Alta Velocità (High Speed Unit) were not interested in testing the radical machine. However, Tommaso Dal Molin was up to the task. Testing occurred on Lake Garda, just off from Desenzano, home of the Reparto Alta Velocità.

Piaggio-Penga-Pc-7-rest-water

The P.7 on Lake Garda for tests. A simple structure connected to hardpoints above the wing was used to raise and lower the aircraft out of the water. More so that most Schneider Trophy racers, the P.7 could only be operated on calm waters.

Using the water propeller, Dal Molin in MM126 was able to raise the nose of the aircraft to a sufficient height to engage the air propeller, but this was not done. The P.7 was unstable planing on the water, and issues were experienced with the clutch for the water propeller. Oil on the clutch caused it to slip, resulting in a loss of power to the water propeller. In addition, the sudden cavitation of the main hydrovanes while planing caused a loss of buoyancy, which resulted in the P.7 suddenly and violently settling back on the water’s surface. Because of the issues, it seems that tests were conducted over only a few days.

There was no cover to easily access the clutch. The needed repairs would require substantial disassembly of the aircraft. By this time, the Air Ministry and Piaggio showed little interested in the P.7, but Pegna wanted to continue its development. Some of the changes Pegna had in mind were adjustable hydrovanes and cooling the engine oil with water rather than using a surface radiator. However, it appears that the repairs were never made. MM126 was stored at Desenzano for a time but was destroyed after a few years. MM127 was taken to Guidonia Montecelio, near Rome, for testing in a water tank to improve the aircraft’s hydrovanes. The aircraft was eventually abandoned, and it is not clear if any tests were ever conducted. MM127, along with other aircraft, was destroyed in 1944—a casualty of World War II.

Piaggio_Pegna_P7_in_hangar

The P.7 surrounded by contemporaries at Desenzano. At left is the Macchi M.39. At right is the Savoia-Marchetti S.65. The Macchi M.52’s wing is in the foreground. Note the P.7’s exhaust stacks protruding above the engine.

Sources:
Some Ideas on Racing Seaplanes (Technical Memorandums National Advisory Committee for Aeronautics No. 691) by Giovanni Pegna (November 1932) 31.4 MB
Schneider Trophy Seaplanes and Flying Boats by Ralph Pegram (2012)
MC 72 & Coppa Schneider Vol. 2 by Igino Coggi (1984)
Schneider Trophy Aircraft 1913–1931 by Derek N. James (1981)
Volare Avanti by Paolo Gavazzi (2000)
Jane’s All the World’s Aircraft 1932 by C. G. Grey (1932)

Farman 18T engine

Farman 18T 18-Cylinder Aircraft Engine

By William Pearce

The rules of the Schneider Trophy Contest stated that any country that won the contest three consecutive times would retain permanent possession of the trophy. By 1930, Britain had two consecutive victories and were favored to win the next contest scheduled for September 1931. Frenchman Jacques P. Schneider had started the contest, and France won the first competition held in 1913. The possibility of losing the contest forever spurred France to action, and the STIAé (service technique et industriel de l’aéronautique, or the Technical and Industrial Service of Aeronautics) ordered at least five aircraft types and three different engines for the 1931 contest. One of the engines ordered was the Farman 18T.

Farman 18T engine

The Farman 18T was specifically designed for installation in the Bernard flying boat. The unusual 18-cylinder engine had no other known applications.

Avions Farman (Farman) was founded in 1908 by brothers Richard, Henri, and Maurice. In October 1917, the company moved to produce engines built under license to support the war effort. The first of these engines was built in mid-1918, and production stopped after World War I. In 1922, Farman started to design their own line of engines under the direction of Charles-Raymond Waseige.

The Farman 18T was designed by Waseige and had an unusual layout. The water-cooled engine had three cylinder banks, each with six cylinders. The left and right cylinder banks were horizontally opposed, with a 180-degree flat angle across the engine’s top side. The lower cylinder extended below the crankcase and was perpendicular to the other cylinder banks. This configuration gave the 18-cylinder engine a T shape.

The engine used a two-piece cast aluminum crankcase that was split vertically. Steel cylinder liners were installed in the cast aluminum, monobloc cylinder banks that were bolted to the crankcase. The four valves of each cylinder were actuated via pairs of rockers by a single overhead camshaft. Each camshaft was driven by a vertical shaft at the rear of the engine.

The 18T used aluminum pistons and had a compression ratio of 6.0 to 1, although some sources say 8.5 to 1. The connecting rods consisted of a master rod for the lower cylinder bank and two articulated rods for the left and right cylinder banks. Each cylinder had two spark plugs, one installed in each side of the cylinder bank. The spark plugs were fired by magnetos driven from the rear of the engine. A nose case at the front of the engine contained the Farman-style bevel propeller reduction gear that turned the propeller at .384 crankshaft speed.

Farman 18T Paris Air Show 1932

The 18T (lower left) was proudly displayed as part of the Farman exhibit at the Salon de l’Aéronautique in November 1932. The other Farman engines are a 350 hp (261 kW) 12G (middle) and a 420 hp (313 kW) 12B (right).

For induction, air passed through carburetors at the rear of the engine and into a centrifugal supercharger that provided approximately 4.4 lb (.3 bar) of boost. The air/fuel mixture flowed from the supercharger into an intake manifold for each cylinder bank. The intake manifolds ran along the bottom of the cylinder bank for the left and right banks and along the right side (when viewed from the non-propeller end) of the lower cylinder bank. The exhaust ports were on the opposite side of the cylinder head from the intake.

The 18T had a 4.72 in (120 mm) bore and stroke. The engine displaced 1,491 cu in (24.4 L) and produced a maximum of 1,480 hp (1,104 kW) at 3,700 rpm. The 18T was rated at 1,200 hp (895 kW) at 3,400 rpm for continuous output. The engine was 65.98 in (1.68 m) long, 44.65 in (1.13 m) wide, 32.56 (.83 m) tall, and weighed 1,069 lb (485 kg).

Two Farman 18T engines were ordered under Contract (Marché) 289/0 (some sources state Marché 269/0) issued in 1930 and valued at 3,583,000 Ғ. The two engines were to power a flying boat built by the Société des avions Bernard (Bernard Aircraft Company). An official designation for the flying boat has not been found, and it was not among the known aircraft ordered for the 1931 Schneider Contest. There is some speculation that a lack of funds prevented the aircraft from being ordered for the 1931 race, but it would be ordered in time for the 1933 race.

Farman 18T Paris Air Show 1932 display

The display at the air show in Paris announced the 18T’s 1,200 hp (895 kW) continuous rating. Note that the supercharger housing extended above the crankcase, which was otherwise the engine’s highest point.

The design of the Bernard flying boat was led by Roger Robert and developed in coordination with the 18T engine. The all-metal aircraft had a low, two-step hull with sponsons protruding from the sides, just behind the cockpit. A long pylon above the cockpit extended along the aircraft’s spine, and the pylon supported the engine nacelle and wings. The engines were installed back-to-back in the middle of the nacelle. The engines’ lower cylinder banks extended into the pylon, and the left and right cylinder banks extended into the cantilever wings, which were mounted to the sides of the nacelle. Surface radiators for engine cooling covered the sides of the pylon, and extension shafts connected the propellers to the engines. The aircraft had a 36 ft 1 in (11.0 m) wingspan and was 35 ft 5 in (10.8 m) long. The engine nacelle was 17 ft 1 in (5.21 m) long. A 12.5 to 1 scale model of the flying boat was tested at the Laboratoire Aérodynamique Eiffel (Eiffel Aerodynamics Laboratory) in Auteuil (near Paris), France.

The 18T engines were bench tested in 1931, but the most power achieved was only 1,350 hp (1,007 kW). While further development was possible, at the time, the chance of France fielding a contestant in the 1931 Schneider Contest was virtually non-existent. The chances of the Bernard flying-boat being built were even worse. Although the aircraft had an estimated top speed of over 435 mph (700 km/h), and a detailed study was submitted to the Service Technique (Technical Service), the flying boat was seen as too radical and was never ordered. The limited funds were needed for the more conventional racers.

The Supermarine S.6B went on to win the 1931 Schneider Contest, giving the British permanent possession of the trophy. The 18T was marketed in 1932 and displayed at the Paris Salon de l’Aéronautique (Air Show) in November. However, there was little commercial interest in the 18T, and the project was brought to a close without the engine ever being flown; most likely, full testing was never completed.

Bernard - Farman 18T Schneider 3-view

Powered by two 18T engines, the Bernard flying boat racer had an estimated top speed of over 435 mph (700 km/h). This speed was substantially faster than the Supermarine S.6B that won the 1931 Schneider race at 340.08 mph (547.31 km/h) and went on to set an absolute speed record at 407.5 mph (655.8 km/h). However, the estimated specifications of unconventional aircraft often fall short of what is actually achieved.

Sources:
Aerosphere 1939 by Glenn D. Angle (1940)
Les Moteurs a Pistons Aeronautiques Francais Tome 1 by Alfred Bodemer and Robert Laugier (1987)
Schneider Trophy Seaplanes and Flying Boats by Ralph Pegram (2012)
Les Avions Bernard by Jean Liron (1990)
Les Avions Farman by Jean Liron (1984)

Packard X-2775 front

Packard X-2775 24-Cylinder Aircraft Engine

By William Pearce

In late 1926, Lt. Alford Joseph Williams approached the Packard Motor Car Company (Packard) regarding a high-power engine for a special aircraft project. Williams was an officer in the United States Navy and believed that air racing contributed directly to the development of front-line fighter aircraft. The United States had won the Schneider Trophy two out of the last three races, and another win would mean permanent retention of the trophy for the US. However, the US government was no longer interested in supporting a Schneider team.

Packard X-2775 front

The original Packard X-2775 (1A-2775) was a direct-drive engine installed in the Kirkham-Williams Racer. A housing extended the propeller shaft to better streamline the engine. Two mounting pads were integral with the crankcase, and a third was part of the timing gear cover at the rear of the engine. Note the vertical intake in the center of the upper Vee.

Williams was assembling a group of investors to fund the design and construction of a private racer to participate in the Schneider contest. In addition, the US Navy was willing to indirectly support the efforts of a private entry. With the Navy willing to cover the development of the engine, Packard agreed to build a powerful engine for Williams’ Schneider racer. On 9 February 1927, the US government officially announced that it would not be sending a team to compete in the 1927 Schneider race, held in Venice, Italy. On 24 March 1927, it was announced that a private group of patriotic sportsmen had formed the Mercury Flying Corporation (MFC) to build a racer for the Schneider Trophy contest that would be piloted by Williams. The aircraft was built by the Kirkham Products Corporation and was known as the Kirkham-Williams Racer.

Packard had started the initial design work on the engine shortly after agreeing to its construction, even though a contract had not been issued. Once the Navy had the funds, Contract No. 3224 was issued to cover the engine’s cost. To speed development of the powerful engine, Packard combined components of two proven V-1500 engines to create a new 24-cylinder engine. The new engine was designated the Packard 1A-2775, but it was also commonly referred to by its Navy designation of X-2775.

Packard X-2775 case drive rod crank

The X-2775’s hexagonal, barrel-type crankcase, timing gear drive and housing, connecting rods, and crankshaft. Note the walls inside of the crankcase, and the crankshaft’s large cheeks that acted as main journals.

The Packard X-2775 was designed by Lionel Melville Woolson. The engine was arranged in an X configuration, with four banks of six cylinders. The upper and lower banks retained the 60-degree bank angle of the V-1500. This left 120-degree bank angles on the sides of the engine. As many V-1500 components were used as possible, including pistons, the basic valve gear, and the induction system. At the front of the X-2775, the propeller shaft ran in an extended housing and was coupled directly to the crankshaft, without any gear reduction. The extended housing allowed for a more streamlined engine installation.

A single-piece, cast aluminum, hexagonal, barrel-type crankcase was used. Two engine mounting pads were provided on each side of the crankcase, and a third pad was incorporated into the side of the timing gear housing, which mounted to the rear of the engine. The crankcase was designed to support landing gear or floats connected to the forwardmost engine mounting pad. Seven integrally cast partitions were provided inside the crankcase. The partitions were hollow at their center and were used to support the crankshaft. The seven single-piece main bearings were made of Babbitt-lined steel rings, shrunk into the crankcase’s partitions, and retained by screws from the outer side of the flanged partition. The partitions had a series of holes around their periphery that allowed for the internal flow of oil as well as enabled assembly of the engine’s connecting rods.

Packard X-2775 manifold and valve spring

Upper image is the valve port arrangement that was integral with the valve and camshaft housing. The drawing includes the ports to circulate hot exhaust gases around the intake manifold to ensure fuel vaporization. The lower image is the unique valve spring arrangement designed by Lionel Woolson. Helically-twisted guides (left) held the seven small springs (center) to make the complete spring set (right).

The crankshaft was positioned about 1.5 in (38 mm) above the crankcase’s centerline and had six crankpins. The crankshaft’s cheeks acted as main journals. The cheeks were perfectly circular and were 7.75 in (197 mm) in diameter. This design increased the main bearing surface area to support the engine’s power but kept the crankshaft the same overall length as the crankshaft used on the V-1500 engine. A longer crankshaft would result in a longer and heavier engine, as well as necessitating the design and manufacture of new valve housings and camshafts. At 161 lb (73 kg), the crankshaft was around twice the weight of the crankshaft used in the V-1500 engine. The X-2775’s crankshaft was inserted through the center of the crankcase for assembly.

Each connecting rod assembly was made up of a master rod and three articulated rods. The end cap, with its two bosses for the articulating rods, was attached to the master rod by four studs. The articulated rods had forked ends that connected to the blade bosses on the master rod. The forked end of each articulated rod was tapped and secured to the master rod by a threaded rod pin. Once assembled, two bolts passed through the connecting rod assembly to further secure its two halves and also secured the pins of the articulated rods. To accommodate the crankshaft being approximately 1.5 in (38 mm) above center in the crankcase, the lower articulated rods were 1.5 in (38 mm) longer than the other rods. When the engine was viewed from the rear, the master rods were attached to pistons in the upper left cylinder bank.

Packard X-2775 section

Sectional view of the X-2775 engine. The engine mount is depicted on the left, and the landing gear or float mount is on the right. Note the spark plug position. The revised engine had provisions for four spark plugs—two on each side of the cylinder.

Individual steel cylinders of welded construction with welded-on steel water jackets were mounted to the crankcase via 10 studs. The cylinder’s combustion chamber had machined valve ports and was welded to the top of the cylinder barrel. Five studs protruded above each cylinder’s combustion chamber and were used to secure the cast aluminum valve and camshaft housing. Each bank of six cylinders had a single valve and camshaft housing.

Each cylinder had two intake and two exhaust valves. The valves were arranged so that one intake and one exhaust valve were on the Vee side of the cylinder, and the pairing was duplicated on the other side of the cylinder. The valve and camshaft housing collected the exhaust gases from two adjacent cylinders and expelled it out one of three exhaust ports. The valve and camshaft housing also had an integral intake manifold that fed three cylinders. The valves for each cylinder bank were actuated by a single overhead camshaft driven by an inclined shaft at the rear of the engine. The two inclined shafts for each Vee engine section were driven by a vertical shaft geared to the crankshaft. The lower vertical shaft was extended to drive one fuel, one water, and four oil pumps. The shafts were enclosed in the timing gear housing that mounted to the back of the engine. The valve covers of the lower cylinders also formed sumps for engine oil collection. Oil was circulated through various passageways in addition to the hollow crankshaft and hollow camshaft. The exhaust valve had a hollow stem for oil cooling.

The valve springs were designed by Woolson and were a unique design. Rather than the valve stem passing through the center of one or two valve springs, a set of seven smaller springs encircled the valve stem. Each of the seven springs was mounted on a guide, and the set was contained in a special retainer. The seven spring guides were given a slight helical twist. The special valve spring set distributed the spring load evenly around the valve stem, reduced the likelihood of a valve failure due to a spring breaking, prevented valve springs from setting, and also rotated the valve during engine operation. The valve rotation was one revolution for about every 40 revolutions of the crankshaft.

Packard X-2775 front and back

Front and rear views of the original X-2775 illustrate that the engine was narrow but rather tall. The ring around the propeller shaft was a fixed attachment point for the engine cowling.

Each cylinder’s combustion chamber had a flat roof with a spark plug on each side of the cylinder. The spark plugs were fired by a battery-powered ignition system via four distributors driven at the rear of the engine. Two distributors were positioned behind each 60-degree cylinder bank Vee. In each cylinder, one spark plug was fired by an upper distributor, and one spark plug was fired by a lower distributor. Separate induction systems were positioned in the upper and lower cylinder Vees. Each system consisted of a central inlet that branched into a forward and rear section. Each section had a carburetor and fed six cylinders. This gave the engine a total of four carburetors—two in each upper and lower vee. Control rods linked the carburetors to the distributors so that ignition timing was altered with throttle position. A port in the valve and camshaft housing fed exhaust gases through a jacket surrounding the manifold to which the carburetor mounted. The exhaust gases heated the intake manifold to better vaporize the incoming fuel charge.

Packard’s V-1500 engine had a 5.375 in (137 mm) bore and a 5.5 in (140 mm) stroke. The X-2775 had the same 5.375 in (137 mm) bore, but the stroke was shortened to 5.0 in (127 mm). However, the three articulated connecting rods had a slightly longer stroke of 5.125 in (130 mm). Each of the six cylinders served by a master rod had a displacement of 113.5 cu in (1.86 L), and each of the 18 cylinders served by an articulated rod had a displacement of 116.3 cu in (1.91 L). The total displacement for the engine was 2,774 cu in (45.5 L). The X-2775 produced a maximum of 1,250 hp (932 kW) at 2,780 rpm and was rated for 1,200 hp (895 kW) at 2,600 rpm. At 2,000 rpm, the engine had an output of 800 hp (597 kW). The X-2775 was 77.5 in (1.97 m) long, 28.3 in wide (.72 m), and 45.2 in (1.15 m) tall. The weight of the initial X-2775 was 1,402 lb (636 kg).

Packard X-2775 no 2 supercharged

The second X-2775 incorporated a Roots-type supercharger driven from the propeller shaft. Difficulty was encountered with fuel metering since the carburetors were positioned on the pressure side of the supercharger. The supercharged engine was never installed in an aircraft.

The X-2775 engine was completed in June 1927 and subsequently passed an acceptance test, which involved the engine running continuously at full throttle for one hour. Williams was involved with testing the X-2775 at Packard to gain experience with its operation. The engine was then shipped out for installation in the Kirkham-Williams Racer, which was finished in late July. The racer and the X-2775 made their first flight on 25 August. Despite achieving speeds around 270 mph (435 km/h), the racer had issues that could not be resolved in time for the Schneider Trophy contest, scheduled to start on 23 September. The Kirkham-Williams Racer was subsequently converted to a land plane, and Williams flew the aircraft over a 3 km (1.9 mi) course unofficially timed at 322.42 mph (518.88 km/h) on 6 November 1927. However, that speed was with the wind, and Williams later stated that the true speed was around 287 mph (462 km/h). Higher speeds had been anticipated. The aircraft was then shipped to the Navy Aircraft Factory (NAF) at Philadelphia, Pennsylvania.

Around late June 1927, rumors indicated that the Schneider competition would be faster than the Kirkham-Williams Racer. As a result, the Navy added a second X-2775 engine to its existing contract with Packard. The second engine incorporated a supercharger for increased power output. In the span of 10 weeks, Packard had designed, constructed, and tested the new engine. The second X-2775 engine was, again, direct drive. However, the propeller shaft also drove a Roots-style supercharger with three rotors (impellers). A central rotor was coaxial with the propeller shaft, and it interacted with an upper and lower rotor that supplied forced induction to the respective upper and lower cylinder banks. For the upper Vee, air was brought in the right side of the supercharger housing and exited the left side, flowing into a manifold routed between the upper cylinder banks. For the lower Vee, the flow was reversed—entering the left side of the supercharger and exiting the right. The supercharged X-2775 weighed around 1,635 lb (742 kg).

Because of the very tight development schedule, the rotors were given generous clearances. This reduced the amount of boost the supercharger generated to only 3.78 psi (.26 bar), which increased the X-2775’s output to 1,300 hp (696 kW) at 2,700 rpm. Tighter rotor tolerances would yield 4.72 psi (.33 bar) of boost and 1,500 hp (1,119 kW) at 2,700 rpm. However, it is not known if improved rotors were ever built. Although completed around August 1927, the supercharged engine was never installed in the Kirkham-Williams Racer.

Packard X-2775 NASM left

The first X-2775 engine was reworked with a propeller gear reduction, new cylinders, new valve housings, and a new induction system. This engine was installed in the Williams Mercury Racer. (NASM image)

The Navy felt that adding a propeller gear reduction to the engine would be more beneficial than the supercharger. To this end, the unsupercharged engine was removed from the Kirkham-Williams Racer as the aircraft was disassembled in the NAF around early 1928. The engine was returned to Packard for modifications. A new aircraft, the Williams Mercury Racer, was to be built, and the first X-2775 engine with the new gear reduction and other modifications would power the machine.

A planetary (epicyclic) gear reduction was built by the Allison Engineering Company in Indianapolis, Indiana. This gear reduction mounted to the front of the engine and turned the propeller at .677 crankshaft speed. Other modifications to the X-2775 included using cylinders and valve housings from an inverted 3A-1500 (the latest V-1500) engine and revising the induction and ignition systems.

The new cylinders increased the engine’s compression (most likely to 7.0 to 1) and had provisions for two spark plugs on both sides of the cylinder. Still, only two spark plugs were used, with one on each side of the cylinder. The new induction was a ram-air system with inlets right behind the propeller. The air flowed into a manifold located deep in the cylinder bank’s Vee. Two groups of two carburetors were mounted to the manifold. Each carburetor distributed the air/fuel mixture to a short manifold that fed three cylinders. The revised ignition system used two magnetos and did away with battery power. The magnetos were mounted to the rear of the engine and driven from the main timing gear. The improved X-2775 was occasionally referred to as the 2A-2775, but it mostly retained the same 1A-2775 Packard designation of its original configuration. The geared X-2775 produced 1,300 hp (969 kW) at 2,700 rpm and weighed around 1,513 lb (686 kg). The gear reduction added about 3 in (76 mm) to the engine, resulting in an overall length of 80.5 in (2.04 m). The width was unchanged at 28.3 in (.72 m), but the revised induction system reduced the engine height slightly to 43.25 in (1.10 m).

Packard X-2775 NASM front

The revised X-2775 took advantage of ram-air induction. Intakes directly behind the Williams Mercury Racer’s spinner fed air into manifolds at the base of the cylinder Vees. Note the spark plugs on both sides of the cylinders. (NASM image)

The updated X-2775 engine was installed in the Williams Mercury Racer in July 1929. In early August, flight testing was attempted on Chesapeake Bay near the Naval Academy in Annapolis, Maryland. While the aircraft was recorded at 106 mph (171 km/h) on the water, it could not lift off. The Williams Mercury Racer was known to be overweight, and there were questions about its float design. The trouble with the racer caused it to be withdrawn from the Schneider Trophy contest, scheduled to start on 6 September in Calshot, England. Later, it was found that the Williams Mercury Racer was some 880 lb (399 kg), or 21%, overweight. Some additional work was done on the aircraft, but no further attempts at flight were made.

Of the original X-2775, Woolson stated that the engine ran for some 30 hours, and at no time was mechanical trouble experienced or any adjustments made. Williams made some comments about the X-2775 losing power, but he otherwise seemed satisfied with the engine and did not report any specific issues. Assistant Secretary of the Navy for Aeronautics David S. Ingalls did not make any negative comments about the engine, but he said Commander Ralph Downs Weyerbacher of the NAF felt that the engine was not satisfactory. However, the basis for Weyerbacher’s opinion has not been found.

There were essentially no X-2775 test engines. Only two engines were made, and the second engine was never installed in any aircraft. The very first X-2775 built was installed in the Kirkham-Williams Racer, and the majority of the issues encounter seemed to come from the aircraft, and not the engine. This scenario repeated itself two years later with the Williams Mercury Racer. The X-2775 did not have any issues propelling the updated racer at over 100 mph (161 km/h) on the surface of the water, but it was the aircraft that was overweight and unable to take flight. If the engine were significantly flawed, it would not have survived its time in the Kirkham-Williams Racer, have been subsequently modified, and then installed in the Williams Mercury Racer. This same engine, Serial No. 1, was preserved and is in storage at the Smithsonian National Air and Space Museum.

Packard offered to build additional X-2775 engines for anyone willing to spend $35,000, but no orders were placed. In the late 1930s, Packard investigated building an updated X-2775 as the 2A-2775. The 2A-2775 was listed as a supercharged engine that produced 1,900 hp (1,417 kW) at 2,800 rpm and weighed 1,722 lb (781 kg). Some sources indicate the engine was built, although no pictures or test data have been found.

Packard X-2775 NASM top

Top view of the X-2775 illustrates the two sets of two carburetors, with each carburetor attached to a manifold for three cylinders. The intake manifold can be seen running under the carburetors. (NASM image)

Sources:
– “The Packard X 24-Cylinder 1500-Hp. Water-Cooled Aircraft Engine” by L. M. Woolson S.A.E. Transactions 1928 Part II. (1928)
– “Internal Combustion Engine” US patent 1,889,583 by Lionel M, Woolson (granted 29 November 1932)
– “Valve-Operating Mechanism” US patent 1,695,726 by Lionel M, Woolson (granted 18 December 1928)
– “Lieut. Alford J. Williams, Jr.—Fast Pursuit and Bombing Planes” Hearings Before a Subcommittee of the Committee on Naval Affairs, United States Senate, Seventy-first Congress, second session, on S. Res. 235 (8, 9, and 10 April 1930)
– “Packard “X” Type Aircraft Engine is Largest in World” Automotive Industries (8 October 1927)
Master Motor Builders by Robert J. Neal (2000)
Packards at Speed by Robert J. Neal (1995)
Jane’s All the World’s Aircraft 1929 by C. G. Gray (1929)
https://airandspace.si.edu/collection-objects/packard-1a-2775-x-24-engine

Williams Mercury Racer

Williams Mercury Seaplane Racer (1929)

By William Pearce

In 1927, Lt. Alford Joseph Williams and the Mercury Flying Corporation (MFC) built the Kirkham-Williams Racer to compete in the Schneider Trophy contest. Although demonstrating competitive high-speed capabilities, the aircraft had handling issues that could not be resolved in time to make the 1927 race. Williams, backed by the MFC, decided to build on the experience with the Kirkham-Williams Racer and make a new aircraft for an attempt on the 3 km (1.9 mi) world speed record.

Williams Mercury Racer model

R. Smith, chief draftsman of the wind tunnel at the Washington Navy Yard, holds a model of the original landplane version of the Williams Mercury Racer. Lt. Al Williams was originally not focused on the Schneider Trophy contest but was later convinced to enter the event.

Although there was no official support from the US government, the US Navy indirectly supported Williams and the MFC’s continued efforts to build a new racer. Williams’ previous racer was designed and built by the Kirkham Products Corporation. However, Williams felt that Kirkham lacked organization, and he was not interested in having the company build another aircraft. Williams had already shipped the previous racer to the Naval Aircraft Factory (NAF) to undergo an analysis on how to improve its speed. With the Navy’s support, the NAF was a natural place to design and build the new racer, which was called the Williams Mercury Racer. The aircraft was also referred to as the NAF Mercury and Mercury-Packard.

In mid-1928, a model of the Williams Mercury Racer landplane was tested in the wind tunnel at the Washington (DC) Navy Yard. However, the decision was made to design a pair of experimental floats and test them on the aircraft, since there was a pressing need to explore high-speed seaplane float designs. It appears all subsequent work on the aircraft was focused on the seaplane version. Williams did not originally intend the Williams Mercury Racer to be used in the 1929 Schneider race. But the US had won the Schneider Trophy two out of the last four races, and another win would mean permanent retention of the trophy. With the Williams Mercury Racer now a seaplane, Williams relented to pressure and agreed to work toward competing in the 1929 Schneider Trophy contest and to attempt a new speed record.

Packard X-2775 NASM

The Packard X-2775 engine installed in the Williams Mercury Racer was actually the same engine originally installed in the Kirkham-Williams Racer. It has been updated with a propeller gear reduction, new induction system, and other improved components. This engine is in storage at the Smithsonian National Air and Space Museum. (NASM image)

Under the supervision of John S. Kean, work on the racer began in September 1928 at the NAF’s facility in Philadelphia, Pennsylvania. On first glance, the Williams Mercury Racer appeared to be a monoplane version of the previous Kirkham-Williams Racer. While some parts such as the engine mount and other hardware were reused, the rest of the aircraft was entirely new. The Williams Mercury Racer was powered by the same Packard X-2775 engine (Packard model 1A-2775) as the Kirkham-Williams Racer, but the engine had been fitted with a .667 propeller gear reduction, and its induction system had been improved. The 24-cylinder X-2775 was rated at 1,300 hp (969 kW), and it was the most powerful engine then available in the US. The X-2775 was water-cooled and had its cylinders arranged in an “X” configuration. The engine turned a ground adjustable Hamilton Standard propeller that was approximately 10 ft 3 in (3.12 m) in diameter. A Hucks-style starter driven by four electric motors engaged the propeller hub to start the engine. Carburetor air intakes were positioned just behind the propeller and in the upper and lower Vees of the engine. The intakes faced forward to take advantage of the ram air effect as the aircraft flew.

The Williams Mercury Racer consisted of a monocoque wooden fuselage built specifically to house the Packard engine. The racer’s braced mid-wing was positioned just before to cockpit. The wing’s upper and lower surfaces were covered in flush surface radiators. A prominent headrest fairing tapered back from the cockpit to the vertical stabilizer, which extended below the aircraft to form a semi-cruciform tail. A nine-gallon (34 L) oil tank was positioned behind the cockpit. The wings and tail were made of wood, while the cowling, control surfaces, and floats were made of aluminum.

Streamlined aluminum fairings covered the metal struts that attached the two floats to the racer. The underside of the floats had additional surface radiators, which provided most of the engine cooling while the aircraft was in the water at low speed. However, the radiators were somewhat fragile and required gentle landings. The floats housed a total of 90 gallons (341 L) of fuel. Some sources state the fuel load was 147 gallons (556 L). The Mercury Williams Racer had an overall length of approximately 27 ft 6 in (8.41 m). The fuselage was 23 ft 7 in (7.19 m) long, and the floats were 19 ft 8 in (5.99 m) long. The wingspan was 28 ft (8.53 m), and the aircraft was 11 ft 9 in (3.58 m) tall. The racer’s forecasted weight was 4,200 lb (1,905 kg) fully loaded. The Williams Mercury Racer had an estimated top speed of around 340 mph (547 km/h). The then-current world speed record stood at 318.620 mph (512.776 km/h), set by Mario de Bernardi on 30 March 1928.

Williams Mercury Racer Packard X-2775

Lt. Al Williams sits in the cockpit of the Williams Mercury Racer during an engine test. The Hucks-style starter is engaged to the propeller hub of the geared Packard X-2775 engine. Note the ducts above and below the spinner that deliver ram air into the intake manifolds situated in the engine Vees.

The completed Williams Mercury Racer debuted on 27 July 1929. On 6 August, the aircraft was shipped by tug to the Naval Academy in Annapolis, Maryland for testing on Chesapeake Bay. Initial taxi tests were conducted on 9 August, and a top speed of 106 mph (171 km/h) was reached. The first flight was to follow the next day, and Williams had boldly planned to make an attempt on the 3 km (1.9 mi) world speed record on either 11 or 12 August. To that end, a course had been set up, and timing equipment was put in place. However, it was soon discovered that spray had damaged the propeller. The propeller was removed for repair, and the flight plans were put on hold.

Although not disclosed at the time, the aircraft was believed to be 460 lb (209 kg) overweight. Williams found that the floats did not have sufficient reserve buoyancy to accommodate the extra weight. The spray that damaged the propeller was a result of the floats plowing into the water. Williams found that efforts to counteract engine torque and keep the aircraft straight as it was initially picking up speed made the left float dig into the water and create more spray. Williams consulted with retired Navy Capt. Holden Chester Richardson, a friend and an expert on floats and hulls. Richardson recommended leaving all controls in a neutral position until a fair amount of speed had been achieved. As the aircraft increased its speed, the water’s planing action on the floats would offset the torque reaction of engine and right the aircraft.

Williams Mercury Racer rear

The racer being offloaded from the tug and onto beaching gear at the Naval Academy in Annapolis, Maryland. The rudder extended below the aircraft and blended with the ventral fin. Note how the fairings for the lower cylinder banks blended into the float supports.

Weather and mechanical issues delayed further testing until 18 August. Williams lifted the Williams Mercury Racer off the water for about 300 ft (91 m) while experiencing a bad vibration and fuel pressure issues. After the engine was shut down, the prop was found damaged again by spray. Like with Williams’ 1927 Schneider attempt, time was quickly running out, and the racer had yet to prove itself a worthy competitor to the other Schneider entrants. Three takeoff attempts on 21 August were aborted for different reasons, the last being a buildup of carbon monoxide in the cockpit that caused Williams to pass out right after he shut off the engine. Attempts to fly on 25 August saw another three aborted takeoffs for different reasons.

The general consensus was that the aircraft’s excessive weight and insufficient reserve buoyancy prevented the racer from flying. With time running out, one final proposal was offered. The Williams Mercury Racer could be immediately shipped to Calshot, England for the Schneider contest, set to begin on 6 September. While en route, a more powerful engine and new floats would be fitted. It is unlikely that the more powerful engine incorporated a supercharger, as supercharger development had given way to the gear reduction used on the X-2775 installed in the Williams Mercury Racer. The gear reduction was interchangeable between engines, but it is not clear what modification had been done to the second X-2775 engine at this stage of development. Regardless, the improved Mercury Williams Racer would then be tested before the race, and, assuming all went well, participate in the event. However, given all the failed attempts at flight and the very uncertain capabilities of the aircraft, the Navy rescinded its offer to transport the racer to England.

Williams Mercury Racer

The completed racer was a fantastic looking aircraft. A top speed of 340 mph (547 km/h) was anticipated, which would have given the British some competition for the Schneider race. However, the speed was probably not enough to win the event.

The Williams Mercury Racer was shipped back to the NAF at Pennsylvania. Williams wanted to install the more powerful engine, which had already been shipped to the NAF, and make an attempt on the 3 km record. The Williams Mercury Racer arrived at the NAF on 1 September 1929, but no work was immediately done on the aircraft. The Navy had not decided what to do with Williams or the aircraft. At the end of October, the Navy gave Williams four months to rework the racer, after which he would be required to focus on his Naval duties and go to sea starting in March 1930.

Studies were made to decrease the Williams Mercury Racer’s weight and improve the aircraft’s cooling system. It was estimated that the suggested changes would lighten the aircraft by 400 lb (181 kg). When the four months were up on 1 March 1930, Assistant Secretary of the Navy for Aeronautics David S. Ingalls felt that enough time, effort, and energy had been spent on the racer and ordered all work to stop. Ingalls also ordered Williams to sea duty. This prompted Williams to resign from the Navy on 7 March 1930. Williams had spent nearly all of his savings on his two attempts at the Schneider contest and knew that the MFC and the Navy had also made a substantial investment in the racer. He wanted to see the project through to some sort of completion, even if it did not result in setting any records.

No more work was done on the Williams Mercury Racer. In April 1930, Williams testified before a subcommittee of the Senate Naval Affairs Committee regarding the racer, his resignation, and other Navy matters. During his testimony, he stated that he wanted another year to finish the aircraft. This time frame would have made the racer ready for the 1931 Schneider Trophy contest, but even in perfect working order it probably would not have been competitive. Williams said the aircraft was 880 lb (399 kg) overweight and that this 21% of extra weight was the reason it could not takeoff. The racer actually weighed 5,080 lb (2,304 kg), rather than the 4,200 lb (1,905 kg) forecasted. Williams said he was initially told that it weighed 4,660 lb (2,114 kg), which was 460 lb (209 kg) more than expected. But Williams thought they could get away with the extra weight. It was only when Williams requested the aircraft to be weighed upon its return to the NAF that its true 5,080-lb (2,304-kg) weight was known.

Williams Mercury Racer Al Williams

The Williams Mercury Racer being towed in after another disappointing test on Chesapeake Bay. Williams stands in the cockpit, knowing his chances of making the 1929 Schneider contest are quickly fading. Note the low position of the floats in the water.

Williams stated that he wanted to take the Williams Mercury Racer to England even if it was not going to be competitive or even fly. Williams said, “I felt we should see it through no matter what the outcome was. If she would not fly over there—take this, to be specific—I was just going to destroy the ship. It could have been done very easily on the water. I intended to smash it up; but I did intend and [was] determined to get to Europe with it. It made no difference to me what the ship did.”

Ingalls also testified before the committee. He had been involved with the Williams Mercury Racer, was a contributor to the MFC, and had friends who were also contributors. Ingalls said that Williams had informed him about the possibility of crashing the Williams Mercury Racer in England if it was unable to fly. Ingalls said that it was ridiculous to send an aircraft to England that may not be able to fly just so that it could be crashed. It was this consideration that led him to withdraw Navy support for sending the aircraft to England. Ingalls also said that of the aircraft’s extra 880 lb (399 kg), around 250 lb (113 kg) was from the NAF’s construction of the aircraft, and around 600 lb (272 kg) was from outside sources, such as Packard for the engine and Hamilton Standard for the propeller. Ingalls reported that Williams supplied the engine’s and propeller’s weight to the NAF, but those values have not been found. Perhaps the original engine weight supplied to the NAF was for the lighter, direct-drive engine and smaller propeller—the combination installed in the Kirkham-Williams Racer.

On 24 June 1930, the Navy purchased the Williams Mercury Racer from the MFC for $1.00. Reportedly, $30,000 was invested by the MFC with another $174,000 of money and resources from the Navy to create the aircraft. It is not clear if the Navy’s investment was just for the Williams Mercury Racer, as the Packard X-2775 engine was also used in the earlier Kirkham-Williams Racer. The Navy stated they acquired the racer for experimental purposes, but nothing more was heard about the aircraft, and the Mercury Williams Racer faded quietly into history.

Williams Mercury Racer taxi

Williams taxis the racer in a wash of spray, most likely damaging the propeller again. Note how the floats are almost entirely submerged, especially the left float. The aircraft being very overweight severely hampered its water handling.

Sources:
Schneider Trophy Seaplanes and Flying Boats by Ralph Pegram (2012)
Wings for the Navy by William F. Trimble (1990)
Master Motor Builders by Robert J. Neal (2000)
Racing Planes and Air Races Volume II 1924–1931 by Reed Kinert (1967)
– “Lieut. Alford J. Williams, Jr.—Fast Pursuit and Bombing Planes” Hearings Before a Subcommittee of the Committee on Naval Affairs, United States Senate, Seventy-first Congress, second session, on S. Res. 235 (8, 9, and 10 April 1930)
– “Making Aircraft Airworthy” by K. M. Painter, Popular Mechanics (October 1928)

Kirkham-Williams Racer no cowl

Kirkham-Williams Seaplane Racer (1927)

By William Pearce

Lt. Alford Joseph Williams was an officer in the United States Navy and a major proponent of aviation. Williams believed that air racing contributed directly to the development of front-line fighter aircraft. In 1923, Williams won the Pulitzer Trophy race and later established a new 3 km (1.9 mi) absolute speed record at 266.59 mph (429.04 km/h). In 1925, Williams finished second in the Pulitzer race, but his main disappointment was not being selected as a race pilot for the Schneider Trophy team. Williams was also not selected for the 1926 Schneider team. That year was a particularly bad showing from the United States despite its advantage of hosting the Schneider contest.

Kirkham-Williams Racer front

The Kirkham-Williams Racer was built to compete in the 1927 Schneider Trophy contest and to capture the world speed record. Note how the large Packard X-24 engine dictated the shape of the aircraft.

Williams could see that racing was not a priority for the US military and decided to take matters into his own hands. In late 1926, Williams sought the support of investors to build a private venture Schneider racer. Since the US had won the Schneider Trophy two out of the last three races, another win would mean permanent retention of the trophy. Williams received further support from various departments in the US Navy, and the Packard Motor Car Company (Packard) was willing to design a new engine provided the Navy paid for it. On 9 February 1927, the US government officially announced that it would not be sending a team to compete in the 1927 Schneider race, held in Venice, Italy. The plans that Williams, the Navy, and Packard had implemented moved forward, and a syndicate to fund the private entry racer was announced on 24 March 1927. The Mercury Flying Corporation (MFC) was formed by patriotic sportsmen for the purpose of building the racer to compete in the 1927 Schneider Trophy contest, with Williams as the pilot.

Although the US government was not directly supporting MFC’s efforts, the US Navy was willing to lend indirect support by transporting the racer to Italy and providing a Packard X-2775 engine for the project. The X-2775 (Packard model 1A-2775) was a 1,200 hp (895 kW), water-cooled, X-24 engine that had been under development by Packard since 1926. The engine was a result of the talks initiated by Williams for a power plant intended specifically for a race aircraft. Ultimately, the engine was covered under a Navy contract. The X-2775 was one of the most powerful engines available at the time.

Kirkham-Williams Racer wing radiator

The racer had some 690 sq ft (64.1 sq m) of surface radiators covering its wings. Fluid flowed from a distributor line at the wing’s leading edge, through the tubes, and into a collector line at the wing’s trailing edge. Tests later indicated that the protruding radiator tubes doubled the drag of the wings.

Williams had decided that the racer should be designed along the same lines as previous Schneider racers built by the Curtiss Aeroplane and Motor Company (Curtiss). MFC contracted the Kirkham Products Corporation (Kirkham) to design and construct the racer. Kirkham’s founder was engineer and former Curtiss employee Charles K. Kirkham, and a number of other former Curtiss employees worked for the company, such as Harry Booth and Arthur Thurston. Booth and Thurston had been closely involved with the racers built at Curtiss. The aircraft was named the Kirkham-Williams Racer, but it was also referred to as the Kirkham-Packard Racer, Kirkham X, and Mercury X.

The Kirkham-Williams Racer was constructed in Kirkham’s faciality in Garden City, on Long Island, New York. The biplane aircraft consisted of a wooden fuselage built around the 24-cylinder Packard engine. The engine mount, firewall, and cowling were made of metal. The upper and lower surfaces of the wooden wings were covered with longitudinal brass tubes to act as surface radiators for cooling the engine’s water and oil. The specially-drawn tubes had an inverted T cross section and protruded about .344 in (8.73 mm) above the wing, creating a corrugated surface. The tubes were .25 in (6.35 mm) wide at their base and .009 in (.23 mm) thick. Around 12,000 ft (3,658 m) of tubing was used, and the oil cooler was positioned on the outer panel of the lower right wing. The water or oil flowed from the wing’s leading edge to a collector at the trailing edge. The aircraft’s twin floats were also made from wood and housed the racer’s main fuel tanks. The floats were attached by steel supports that were covered with streamlined aluminum fairings. The forward float supports were mounted directly to special pads on the engine. The cockpit was positioned behind the upper wing, and a headrest was faired back along the top of the fuselage into the vertical stabilizer. A framed windscreen protected the pilot. A small ventral fin extended below the aircraft’s tail.

Kirkham-Williams Racer starter

The Packard X-2775 engine barely fit into the racer. The engine cowling mounted to arched supports running from the cylinder banks to a ring around the propeller shaft. The Hucks-style starter, powered by four electric motors, is connected to the propeller hub. Note that the forward float strut is mounted to the engine’s crankcase.

The Kirkham-Williams Racer had an overall length of 26 ft 9 in (8.15 m). The fuselage was 22 ft 9 in (6.93 m) long, and the floats were 21 ft 3 in long (6.48 m). The upper wing had a span of 29 ft 10 in (9.09 m), and the lower wing’s span was 24 ft 3 in (7.39 m). The racer was 10 ft 9 in (3.28 m) tall and weighed 4,000 lb (1,814 kg) empty and 4,600 lb (2,087 kg) fully loaded. The aircraft carried 60 gallons (227 L) of fuel, 35 gallons (132 L) of water, and 15 gallons (57 L) of oil. The direct-drive Packard engine turned a two-blade, ground-adjustable, metal propeller that was 8 ft 6 in (2.59 m) in diameter and built by Hamilton Standard. A Hucks-style starter driven by four electric motors engaged the propeller hub to start the engine. Carburetor air intakes were positioned in the upper and lower engine Vees and were basically flush with the cowling’s surface.

Packard was involved with the aircraft’s construction, and Williams was involved with the engine’s development. The Kirkham-Williams Racer was finished in mid-July 1927 and transported later that month to Manhassest Bay, on the north side of Long Island. Weather delayed the first tests until 31 July. Taxi tests revealed that the float design was flawed and caused a large amount of spray to cover the aircraft and cockpit. The spray resulted in damage to the propeller during a high-speed taxi test. In addition, the aircraft was around 450 lb (204 kg) overweight.

Kirkham-Williams Racer launch

Lt. Al Williams prepares the racer for a test on Manhassest Bay. The cockpit was designed around Williams, and he was the only one to taxi or fly the aircraft. Note the support running between the vertical and horizontal stabilizers.

With the Schneider race just over a month away, little time was left to properly test the aircraft and transport it halfway around the world. Williams requested a postponement of the Schneider race for one month, but the British contingent declined the request. To make matters worse, Williams had been very optimistic about the aircraft’s test schedule and repeatedly promised an attempt on the world speed record. Issues with the Kirkham-Williams Racer resulted in a continual push-back of Williams’ proposed speed flights.

With a repaired propeller and new floats, the Kirkham-Williams Racer was ready for additional tests on 16 August. An oil leak and air in the water-cooling system caused Williams to cancel the day’s activities before any real testing had been done. On 17 August, high-speed taxi tests were finally sufficiently completed. Williams announced that the Kirkham-Williams Racer’s first flight would be the following day, but unfavorable weather caused that date to be pushed back. The racer’s first flight was on 25 August, and it should be noted that this was the first flight for the X-2775 engine as well. Some sources state that Williams made two speed runs at an estimated 250 mph (402 km/h). However, Williams stated that no speed runs were attempted on the first flight. While 250 mph (402 km/h) is an impressive speed for the time, it was most likely an estimation made by observers and not achieved over a set course. The second flight that day was cut short because of engine cooling issues caused by air in the cooling system.

Kirkham-Williams Racer runup

Williams is in the cockpit running up the X-2775 engine. The registration X-648 has been applied to the tail. The fuselage was painted blue, with the wings, floats, and rudder painted gold. Note the rather imperfect finish of the fuselage, just before the tail.

Unfavorable weather resulted in more delays, and it was not until 29 August that Williams was able to take the Kirkham-Williams Racer up for another flight during a brief break between two storm fronts. Williams made a high-speed run, and the racer was unofficially timed at 275 mph (443 km/h). Later, Williams would say the speed was probably around 269 mph (433 km/h), but he and others felt the aircraft was capable of 290 mph (467 km/h). Weather again caused delays, and three takeoff attempts on 3 September had to be aborted on account of pleasure boats straying into the aircraft’s path and causing wakes.

On 4 September, a good, extended flight was made, after which Williams reported the aircraft was nose-heavy and became increasingly destabilized at speeds above 200 mph. The issue was with the orientation of the floats. Modifications were made, and the aircraft flew again on 6 September. Williams reported improved handling, but some issues remained. The Navy had held the cruiser USS Trenton at the Brooklyn Navy Yard with the intention of transporting the Kirkham-Williams Racer to Italy in time for the Schneider contest, which was to start on 23 September. However, Williams cancelled any attempts to make the Schneider race on 9 September, citing the nose-heaviness and also float vibrations.

Kirkham-Williams Racer no cowl

Williams stands on the float, with work going on presumably to clear air from the cooling system, which was a reoccurring issue. The copper radiators covered almost all of the wing’s surface area. Note that the interplane struts protruded slightly above the wings.

During the time period above, it was felt that the Kirkham-Williams Racer may not have been competitive, and Packard was asked to build a more powerful engine. In the span of 10 weeks, Packard designed, constructed, and tested a supercharged X-2775 engine. The Roots-type supercharger was installed on the front of the engine and driven from the propeller shaft. Liberal tolerances were used because of the lack of time, and the supercharger generated only 3.78 psi (.26 bar) of boost. The supercharged engine produced 1,300 hp (696 kW), which was only a slight power increase. The engine was not installed, because the minor gain in power was offset by the added weight and complexity of the supercharger system.

With the Schneider race out of reach, the Kirkham-Williams Racer was converted to a landplane with the intent to set a new world speed record. The floats were removed, and two main wheels attached to streamlined struts were installed under the engine. A tail skid replaced the small fin under the aircraft’s rudder. In addition, the X-2775 engine was fitted with a new cowling and spinner that gave the aircraft a more streamlined nose.

Kirkham-Williams Racer landplane front

Williams reported making four emergency landings in the racer at Mitchel Field, but the causes of the forced landings have not been found. The aircraft was fitted with the same direct-drive X-2775 engine as the seaplane. The intake of the upper Vee engine section can just be seen above the cowling.

The modifications to the Kirkham-Williams Racer were completed by late October 1927, and the aircraft was taken to Mitchel Field on Long Island, New York. Williams’ initial tests found the plane heavy with a landing speed of around 100 mph (161 km/h). Williams felt Mitchel Field was not an ideal place for experimental work with the aircraft, but the MFC did not have funds to seek a better location. Williams ended up making four forced landings at Mitchel Field in the Kirkham-Williams Racer.

On 6 November, Williams flew the aircraft over a 3 km (1.9 mi) course and was unofficially timed at 322.42 mph (518.88 km/h). This speed was significantly faster than the then-current records, which were 278.37 mph (447.99 km/h) set by Florentin Bonnet on 11 November 1924 for landplanes, and an absolute record of 297.70 mph (479.10 km/h) set by Mario de Bernardi on 4 November 1927. Some were skeptical of Williams’ speed, especially since it was achieved in only one direction and with the wind reportedly blowing at 40 mph (64 km/h). Williams announced that an official attempt on the record would soon be made, but no further flights of the Kirkham-Williams Racer were recorded. Later, Williams stated that the racer’s still-air speed on the 6 November 1927 run was around 287 mph (462 km/h), which was much lower than anticipated.

Williams had the aircraft disassembled and shipped to the Naval Aircraft Factory (NAF) in Philadelphia, Pennsylvania to further evaluate ways to improve the racer’s speed. A section of the wing was removed and tested by the National Advisory Committee for Aeronautics in their wind tunnel at Langley Field, Virginia. The test results indicated that the corrugated surface radiators decreased lift, doubled drag, and slowed the aircraft by some 20 mph (32 km/h). While at the NAF, the disassembled Kirkham-Williams Racer was used as the basis for Williams’ 1929 high-speed aircraft—the Williams Mercury Racer.

Kirkham-Williams Racer landplane

In landplane form, the Kirkham-Williams Racer had a more streamlined nose and an added tailskid. The machine looked every bit a racer and was one of the fastest aircraft in the world, even at only 287 mph.

Sources:
Schneider Trophy Seaplanes and Flying Boats by Ralph Pegram (2012)
Schneider Trophy Racers by Robert Hirsch (1993)
Master Motor Builders by Robert J. Neal (2000)
Racing Planes and Air Races Volume II 1924–1931 by Reed Kinert (1967)
Full Scale Investigation of the Drag of a Wing Radiator by Fred E. Weick (September 1929)
– “Lieut. Williams’ Racing Seaplane” by George F. McLaughlin, Aero Digest (September 1927)
– “Lieut. Alford J. Williams, Jr.—Fast Pursuit and Bombing Planes” Hearings Before a Subcommittee of the Committee on Naval Affairs, United States Senate, Seventy-first Congress, second session, on S. Res. 235 (8, 9, and 10 April 1930)

pander-s4-engine-run

Pander S.4 Postjager Trimotor Mailplane

By William Pearce

In the early 1930s, Dutch pilot Dirk Asjes was disappointed with the slow development of Dutch airmail flights and Fokker aircraft. Asjes sketched out an aircraft design and asked the aircraft manufacturer Pander to build a special mailplane to compete with KLM (Koninklijke Luchtvaart Maatschappij or Royal Dutch Airlines) mail and passenger service. Officially, Pander was called the Nederlandse Fabriek van Vliegtuigen H. Pander & Zonen (H. Pander & Son Dutch Aircraft Company). Pander was a furniture company that had expanded to aircraft construction in 1924 when its owner, Harmen Pander, purchased the bankrupt VIH (Vliegtuig Industrie Holland or Holland Aircraft Industry).

pander-s4-engine-run

The Pander S.4 Postjager displays its clean lines. The trimotor aircraft was purpose-built as a mail carrier to fly from Amsterdam to Batavia.

Airmail service to the Dutch East Indies involved using the relatively slow Fokker F.XVIII, which had a top speed of 149 mph (240 km/h). To improve service, KLM ordered the Fokker F.XX Zilvermeeuw, which had a top speed of 190 mph (305 km/h). While the F.XX was being built, Pander took up the challenge to build a faster aircraft solely to transport mail. Pander’s new design was the S.4 Postjager, and financial support came from a few Dutch shipping companies who hoped to break KLM’s monopoly on air transport to the East Indies.

The Pander S.4 Postjager was designed by Theodorus (Theo) Slot, who was originally with VIH. The aircraft was a low-wing trimotor with retractable main gear. The S.4 was made almost entirely of wood. The aircraft was powered by three 420 hp (313 kW) Wright Whirlwind R-975 engines. The aircraft’s interior was divided into three compartments: cockpit, radio room, and mail cargo hold.

pander-s4-takeoff

On paper, the S.4 appeared to be an impressive, purpose-built aircraft that could improve airmail service for the Netherlands. In practice, the aircraft never had an opportunity to fully demonstrate its capabilities without outside difficulties hindering its performance.

The S.4 used external ailerons that mounted above the wings’ trailing edge. Sometimes called “park bench” ailerons because of their appearance, they are often mistaken for Flettner tabs. A Flettner tab is a supplementary control surface that attaches to and assists the primary control surface. By contrast, a “park bench” aileron is the primary control surface, and there is no other control surface integral with the wing. External ailerons operated in the undisturbed airflow apart from the wing and were more responsive during minor control inputs or during slow flight. In addition, external ailerons allowed the use of full-span flaps to give the aircraft a low landing speed. However, external ailerons had a tendency to flutter at higher speeds, potentially causing catastrophic damage to the aircraft (but flutter was not well understood in the 1930s). On the S.4, the flaps extended from the engine nacelles to near the wingtips.

The S.4 had a wingspan of 54 ft 6 in (16.6 m) and was 41 ft (12.5 m) long. The aircraft had a maximum speed of 224 mph (360 km/h), a cruising speed of 186 mph (300 km/h), and a landing speed of 60 mph (97 km/h). The S.4 was designed to carry 1,102 lb (500 kg) of mail. It had an empty weight of around 6,669 lb (3,025 kg) and a loaded weight of around 12,125 lb (5,200 kg). Six fuel tanks, three in each wing, carried a total of 555 gallons (2,100 L). The aircraft had a range of 1,510 miles (2,430 km) and a ceiling of 17,717 ft (5,400 m).

pander-s4-underside

This underside view of the S.4 shows its PH-OST registration. Also visible are the external ailerons attached to the wings’ upper surfaces. The aircraft’s slot flaps (not visible) extended from the engine nacelle to near the wingtip.

Cleverly registered as PH-OST, the completed S.4 mailplane made its public debut on 23 September 1933. The Fokker F.XX also made its debut at the event, which was attended by Prince Henry of the Netherlands. The S.4 flew the following month, when Gerrit Geijsendorffer and Funker van Straaten made the maiden flight on 6 October 1933. Flight testing went well, and on 9 December 1933, the S.4 departed on an 8,700-mile (14,000-km) flight from Amsterdam to Batavia (now Jakarta, Indonesia). Flown by Geijsendorffer, Asjes, and van Straaten, this flight was a special run to demonstrate the aircraft’s speed and range and also to deliver 596 lb (270 kg) of Christmas mail (made up of some 51,000 letters and postcards) to the Dutch colony. At the time, the Fokker F.XX was being prepared for the same flight.

The S.4 had made a scheduled stopover in Rome, Italy and was proceeding to Athens, Greece when the right engine lost oil pressure. The aircraft made an emergency landing in Grottaglie, Italy, and inspection revealed that the right engine needed to be replaced. With no engines available anywhere in Europe, one was shipped from the United States and set to arrive on 22 December. This setback put the Christmas mail service in jeopardy. To make sure the mail was delivered, arrangements were made for the F.XX to pick up the S.4’s mail and continue to Batavia. But, the F.XX had its own engine issues before it even took off. This left the Fokker F.XVIII, the aircraft the S.4 and F.XX were meant to replace, as the only alternative. A F.XVIII picked up the mail and continued to Batavia with enough time for Christmas delivery. The failed Christmas flight was a huge embarrassment for both the S.4 and F.XX programs.

pander-s4-ground-side

This side view of the S.4, now named Panderjager, shows the aircraft as it appeared in the MacRobertson Race. Note the “park bench” aileron extending above the wing.

The repaired S.4 set out for Batavia on 27 December and arrived on 31 December. It made the return flight, leaving Batavia on 5 January 1934 and arriving in Amsterdam on 11 January. Although the S.4 averaged 181 mph (291 km/h) on the flight from Batavia, the aircraft’s mail flight failed to impress, and the S,4 was not put into service. Pander decided to prepare the aircraft for the MacRobertson Trophy Air Race flown from London to Melbourne, Australia.

The MacRobertson Race started on 20 October 1934 and covered some 11,300 miles (18,200 km). For the race, the S.4 was flown by Geijsendorffer, Asjes, and Pieter Pronk and carried race number 6. The aircraft had been renamed Panderjager, but some referred to it as the Pechjager (“pech” meaning “bad luck” and “breakdown”). After leaving Mildenhall airfield in England, the S.4 arrived in Bagdad, Iraq in third place at the end of the first day of the race. The next day, the aircraft proceeded to Allahabad, India, still in third place. Upon touchdown in Allahabad, the left gear collapsed, resulting in bent left and front propellers and a damaged left cowling and main gear.

pander-s4-rear

This rear view of the S.4 shows the external brace on the horizontal stabilizer and the elevators’ trim tabs. The image also provides a good view of the “park bench” ailerons.

Allahabad did not have the facilities to repair the S.4. Geijsendorffer took the propellers and traveled by train to the KLM depot in Calcutta (now Kolkata), India to make the needed repairs. This delay took the S.4 out of competition, but the decision was made to finish the race. Repairs were completed, and the S.4 was ready to fly on the evening of 26 October 1934. A service vehicle towing a light was positioned across the field from the S.4 to illuminate its path. The S.4’s crew found the light distracting and asked for it to be shut off, as the aircraft could provide its own lighting.

Once the service vehicle’s light was shut off, the S.4 prepared for takeoff. Unfortunately, the crew of the service vehicle misunderstood the instructions. They thought they were to proceed to the S.4 and illuminate the aircraft from behind. As they made their way toward the S.4 in darkness, the aircraft began its takeoff run. At about 99 mph (160 km/h), the S.4’s right wing struck the service vehicle. Fuel spilled from the ruptured wing and quickly ignited as the S.4 skidded 427 ft (130 m) to a stop. Pronk was uninjured, and Geijsendorffer and Asjes escaped with minor burns, but the S.4 was completely destroyed by the fire. The two operators of the service vehicle were severely injured.

Pander planned to convert the S.4 to a scout or bomber after the race and sell it to the military. With the loss of the S.4, there was no aircraft to sell, and Pander was not able to recover its expenses. The company went out of business a short time later.

The S.4 sits at Allahabad, India with bent propellers on its front and left engines. The de Havilland DH 88 Comet “Black Magic” suffered engine trouble, and work to repair its engine was underway as it sat next to the S.4. The S.4 never left Allahabad.

The S.4 sits at Allahabad, India with bent propellers on its front and left engines. The de Havilland DH 88 Comet “Black Magic” suffered engine trouble, and work to repair its engine was underway as it sat next to the S.4. The S.4 never left Allahabad.

Sources:
Nederlandse Vliegtuigen Deel 2 by Theo Wesselink (2014)
Jane’s All the World’s Aircraft 1934 by G. G. Grey (1934)
Blue Wings Orange Skies by Ryan K. Noppen (2016)
– “High-Speed Mail Machine” Flight (7 September 1933)
– “The Aerial Phost” Flight (5 October 1933)
– “Opening of Amsterdam Aero Club’s New Clubhouse” Flight (28 September 1933)
– “The Pander Postjager Pauses” Flight (14 December 1933)
http://www.aviacrash.nl/paginas/panderjager.htm
https://de.wikipedia.org/wiki/Pander_S4
https://en.wikipedia.org/wiki/Pander_%26_Son

savoia-marchetti-s65-calshot

Savoia-Marchetti S.65 Schneider Racer

By William Pearce

After the Italian team was defeated on its home turf at Venice, Italy in the 1927 Schneider Trophy Race, the Italian Ministero dell’Aeronautica (Air Ministry) sought to ensure victory for the 1929 race. The Ministero dell’Aeronautica instituted programs to enhance aircraft, engines, and pilot training leading up to the 1929 Schneider race. Early in 1929, the Ministero dell’Aeronautica requested racing aircraft designs from major manufacturers and encouraged unorthodox configurations.

savoia-mrachetti-s65-orig-config

The Savoia-Marchetti S.65 in its original configuration. Note the single strut extending from each float to the tail, the short tail and rudder, and the short windscreen.

Alessandro Marchetti was the chief designer for Savoia-Marchetti and was preoccupied with the design of the long-range S.64 aircraft. Originally, he did not submit a Schneider racer design, but the Ministero dell’Aeronautica encouraged him to reconsider. Soon after, Marchetti submitted the rather unorthodox S.65 design. On 24 March 1928, the Ministero dell’Aeronautica ordered two S.65 aircraft and allocated them the serial numbers MM 101 and MM 102.

The Savoia-Marchetti S.65 was a low-wing, tandem-engine, twin-boom monoplane that utilized two long, narrow floats. The aircraft was designed to incorporate the largest amount of power in the smallest package. The S.65’s tension rod and wire-braced wings were made of wood and almost completely covered with copper surface radiators. The floats were made of wood (some say aluminum), had a relatively flat bottom, and housed the S.65’s fuel tanks. The floats were around 28 ft 8 in (8.75 m) long and were mounted on struts. Originally, one strut extended from the rear of each float to the tail, but a second strut was later added.

savoia-marchetti-s65-2nd-config

The S.65 has been modified with an additional strut extending from each float to the tail. The tail and rudder have also been extended below the horizontal stabilizer. Note that the windscreen has not changed, that the rudder has a rather square lower trailing edge, and that there are no handholds in the wingtips.

A narrow boom extended behind each wing to support the tail. The boom was hollow and had flight cables running through its interior. Sources disagree on whether the booms were made of metal or wood. The horizontal stabilizer was mounted between the ends of the booms. The vertical stabilizer was positioned in the center of the horizontal stabilizer. Originally, the rudder and tail extended only above the horizontal stabilizer, and the rudder was notched to clear the elevator. Later, the tail and rudder were enlarged and extended below the horizontal stabilizer, and the elevator was notched to clear the rudder. The tail and all control surfaces were made of wood and were fabric-covered.

Attached to the wing was a small fuselage nacelle that housed two Isotta Fraschini Asso 1-500 engines. The engines were mounted in a push-pull configuration with one engine in front of the cockpit and the other behind. The nacelle was made of a tubular steel frame and covered with aluminum panels. Oil coolers were mounted on both sides of the cockpit between the engines. Two windows to improve the pilot’s lateral visibility were positioned above each oil cooler. Just behind the front engine was a windscreen for the cockpit. Initially, a short windscreen was installed, but this was later replaced by a longer, more streamlined unit. The fuselage nacelle was around 18 ft (5.48 m) long, including the propeller spinners.

isotta-fraschini-1-500-s65-engine

The 1,050 hp (783 kW) Isotta Fraschini Asso 1-500 engine. It is unclear how much this engine differed internally from a standard Asso 500 engine. The three cantilever mounts and the nearly-flush rear of the engine can clearly be seen. The exhaust ports have been relocated from the outer side of the cylinder head to the Vee side. A water pump and magneto are just visible on the extended gear reduction case. The vertical ribbing on the lower crankcase served to increase its strength.

The S.65’s Asso 1-500 V-12 engines were based on the Asso 500 Ri engine and were heavily modified by Giustino Cattaneo, head engineer at Isotta Fraschini. The engine’s crankcase was ribbed and strengthened to become a structural member of the S.65’s fuselage nacelle. Each engine mounted directly to a steel bulkhead on the end of the cockpit via three cantilever supports. The rear of the engine sat flush with the bulkhead. At the front of the engine was an extended gear reduction case which allowed for a streamlined cowling. Engine accessories, such as the two water pumps and two magnetos, were mounted to the gear case. Each Asso 1-500 engine produced 1,050 hp (783 kW) at 3,000 rpm.

At the bottom of each side of the cowling were two inlets. Air flowed from each inlet into a carburetor and then into three cylinders of the engine. Exhaust ports were located on the Vee side of the engine, and the exhaust gases were expelled up though the top of the cowling. Both engines turned counter-clockwise. Since the rear engine was installed backward, the propellers of each engine turned in opposite directions relative to one another. This installation effectively cancelled out the propeller torque that had been an issue for a number of Schneider racers. The metal, two-blade, fixed pitch propellers had a diameter of approximately 7 ft 5 in (2.26 m). The rear propeller’s spinner was about one-third longer than the front spinner.

savoia-marchetti-s65-calshot

The S.65 as seen at Calshot, England. The long windscreen has now been installed. The lower trailing edge of the rudder is now rounded, and the wingtips now have handholds. This image gives a good view of the surface radiators that cover nearly all of the wings. Also visible is the rectangular cover of the exhaust ports between the cylinder banks.

Italian sources and drawings from Savoia-Marchetti list the S.65 as having a wingspan of 31 ft 2 in (9.5 m) and a length of 35 ft 1 in (10.7 m). However, other sources often cite a wingspan of 33 ft (10.05 m) and a length of 29 ft (8.83 m). It is not entirely clear which figures are correct. The weight of the aircraft was approximately 5,071 lb (2,300 kg) empty and 6,173 lb (2,800 kg) loaded. The top speed of the S.65 was estimated between 375 and 400 mph (600 and 645 km/h).

In mid-1929, Alessandro Passaleva, one of Savoia-Marchetti’s pilots, tested the first S.65 (MM 101) on Lake Maggiore, near the company’s factory in Sesto Calende, Italy. Although the aircraft was not flown, Passaleva recommended a number of changes to stiffen and improve the S.65’s tail. The second S.65 (MM 102) was modified with the additional tail brace and extended rudder and tail. It is doubtful that MM 101 was ever flown or that MM 102 was flown on Lake Maggiore. MM 102 was delivered to the Reparto Alta Velocità (High Speed Unit) at Desenzano on Lake Garda in July 1929.

Initial flight tests of the S.65 were conducted by Tommaso Dal Molin and began in late July 1929. This is most likely the first time an S.65 was flown. Dal Molin was an experienced pilot and also small enough to fit inside the S.65’s very cramped cockpit. Some accounts state that Dal Molin did not bother with a parachute because the cockpit was so small, and the rear propeller made bailing out nearly impossible. A number of issues were encountered with the aircraft’s engines and cooling system. In addition, exhaust fumes constantly entered the cockpit.

savoia-marchetti-s65-calshot-runup

This image shows the S.65’s rear engine being run-up at Calshot. The oil radiator is clearly seen between the two engines, and it gives some perspective as to the small size of the cockpit. Note the various engine accessories mounted to the extended gear reduction case.

It was soon obvious that the S.65 would not be ready in time for the Schneider Trophy Race held on 6–7 September 1929 in Calshot, England. However, the Italians decided to send the aircraft anyway, to give the British team something to consider. Before the S.65 arrived at Calshot, the lower rudder extension was rounded; the longer windscreen was installed, and handholds were added to the wingtips. During the races, the S.65 MM 102 was displayed, and its rear engine was run-up on at least one occasion. Some saw the S.65 as a sign of future high-speed aircraft to come.

Italy had developed four new aircraft for the 1929 Schneider Trophy Race: Macchi M.67, FIAT C.29, Savoia-Marchetti S.65, and Piaggio P.7. The end result was that Italian resources were spread too thin, and none of their aircraft were developed to the point of offering serious competition to the British effort, which was victorious. Once back in Italy, the head of the Reparto Alta Velocità, Mario Bernasconi, decided to recover some pride by making an attempt on the world speed record. Britain had just set a new record on 12 September 1929 at 357.7 mph (575.7 km/h) in its Schneider race-winning Supermarine S6 (N247) piloted by Augustus Orelbar.

savoia-marchetti-s65-dal-molin-calshot

Tommaso Dal Molin poses in front of the S.65. Note the longer windscreen and the side windows just above the oil cooler. Each rectangular port on the cowling leads to a carburetor. Also visible are the louvers that cover the cowling.

The S.65 underwent further refinements in late 1929, and it was believed that the aircraft could exceed the S6’s speed by a reasonable margin. It appears the aircraft was fitted with new aluminum (duralumin), V-bottom floats. In addition, the engine cowling had what appear to be six exhaust ports positioned on each side. Exhaust fumes entering the cockpit was an issue due to the central exhaust location, and relocating the ports to the engine sides (their original location in the Asso 500 engine) would help solve the issue. The carburetor intakes were not changed.

Dal Molin took the S.65 on a test flight from Lake Garda on 17 January 1930 to prepare for his speed record attempt the following day. On 18 January, Dal Molin made three takoff attempts, which were all aborted due to excessive yaw. On the fourth attempt, the S.65 became airborne and then pitched up at an extreme angle. The aircraft stalled some 80 to 165 ft (25 to 50 m) above the water and crashed into the lake. Rescue vessels arrived quickly, but the S.65 with Dal Molin still aboard had quickly sunk 330 ft (100 m) to the bottom of the lake. It was Tommaso Dal Molin’s 28th birthday. A special recovery vessel called the Artigilo retrieved the S.65 on 29 January. Dal Molin’s body was recovered on 30 January. While the exact cause of the crash was never determined, many believe the elevator jammed, resulting in the abrupt pitch up and subsequent stall.

Note: As mentioned above, many sources disagree on various aspects of the S.65. For example, sources (some of which were not used in this article) list the wing spars as being made from four different materials: duralumin, walnut, mahogany, and spruce. While images were closely scrutinized to give an accurate account of the S.65 in this article, only so much can be determined from analyzing a grainy, 85-year-old image. In addition, some sources claim that only one S.65 was built (MM 102). Others say construction of MM 101 was started but never completed, and still others contend that MM 101 was completed and stored at the Reparto Alta Velocità at Lake Garda until 1939.

savoia-mrachetti-s65-recovery

The remains of the S.65 after it was recovered from Lake Garda and placed onboard the Artigilo. The rear engine is in the foreground. Note what appear to be exhaust ports along the sides of the cowling. The aircraft’s fuselage seems to be rather undamaged. Reportedly, the S.65 sank quickly, and some sources claim that Dal Molin could not swim.

Sources:
Schneider Trophy Seaplanes and Flying Boats by Ralph Pegram (2012)
Aeroplani S.I.A.I. 1915–1945 by Giorgio Bignozzi and Roberto Gentilli (1920)
Schneider Trophy Aircraft 1913–1931 by Derek N. James (1981)
MC 72 & Coppa Schneider by Igino Coggi (1984)
L’epopea del reparto alta velocità by Manlio Bendoni (1971)
http://wwwteamgrs-marco.blogspot.com/2015/04/il-recupero-della-salma-del-pilota.html

Wedell-Williams Model 45

Wedell-Williams Model 45 Racer

By William Pearce

In 1932, the Wedell-Williams Air Service Model 44 established itself as one of the premier air racers. The Model 44 was a fast, sleek monoplane with fixed gear. The aircraft was designed by Jimmie Wedell, an experienced pilot and air racer. The Weddell-Williams company was founded in 1929 when Jimmie Wedell and his brother Walter gained the financial backing of millionaire Harry Williams. Operating out of Patterson, Louisiana, Wedell-Williams Air Service was established to provide a wide range of aeronautical services that included constructing new aircraft, flight instruction, and passenger and mail service. The best way to prove one’s aircraft design abilities and gain publicity was to create a record breaking air racer—the Model 44 was exactly that. However, progress in aviation was swift, so it was in 1933 that Wedell began to design his next racer: the Model 45.

Wedell-Williams Model 45 side

The Model 45 followed the Wedell-Williams design concept that was so well executed in their Model 44 racer. It was a simple concept: a big engine in a sleek airframe resulting in a fast aircraft.

The Model 45 followed the same conventional layout as the Model 44, but the aircraft was further refined with a cantilever wing and retractable undercarriage. The Model 45 consisted of a welded chrome-molybdenum steel tube fuselage. The front and tail of the aircraft were skinned in aluminum. Fabric covered the rest of the fuselage, from in front of the cockpit back to the tail. The Model 45’s wing had a wooden spar; the rest of the structure was made from metal and skinned with aluminum. The main gear retracted inward to be fully enclosed within the wing. The aircraft’s tail skid retracted into the fuselage. Each side of the cockpit had a plexiglass panel that could slide up to fully enclose the pilot.

The Model 45 had a 26 ft 8.5 in (8.1 m) wingspan and was 24 ft long (7.3 m). The aircraft had a race weight of around 3,000 lb (1,360 kg). The Model 45 was intended to have a 14-cylinder Pratt & Whitney (P&W) R-1535 Twin Wasp radial engine of 825 hp (615 kW), and its top speed was anticipated to be over 300 mph (483 km/h). However, the R-1535 engine was not ready, so a nine-cylinder P&W R-985 Wasp Jr. engine of 535 hp (399 kW) was installed in its place.

Wedell-Williams Model 45 early

This photo of the Model 45 was taken shortly after the aircraft was built in Patterson, Louisiana in 1933. Note the smooth cowling covering the R-985 engine. Jimmie Wedell stands by the side of the aircraft.

Wedell took the Model 45 (registered as NR62Y) up for its first flight on 28 June 1933. The R-985 engine caused the aircraft to be underpowered and tail-heavy. Very little flight testing was accomplished because Wedell had entered the Model 45 in the Bendix Trophy Race, which was scheduled for 1 July. The 1933 race was run from New York to Los Angeles. Departing for New York, Wedell made it from Patterson, Louisiana to Atlanta, Georgia (about 500 miles / 805 km) before he turned back. Wedell decided the aircraft would not be competitive with its current engine. Instead, he flew a Model 44 (No. 44) and finished the race in second place, behind Roscoe Turner in his Wedell-Williams Model 44 (No. 2).

With the R-1535 still delayed, a nine-cylinder, 800 hp (597 kW) P&W R-1340 Wasp Sr. engine was installed on the Model 45 in place of the smaller engine. The R-1340 provided sufficient power for the aircraft and restored its proper balance. While the two engines used the same mounts, the R-1340 had a larger diameter than the R-985 and required a new cowling. The smooth cowling covering the R-985 engine was replaced by a larger cowling with bumps around its diameter to provide clearance for the engine’s rocker covers. The same engines were used in the Model 44, so the entire engine package (including cowling) could be swapped between the aircraft. An 8 ft 2 in (2.5 m) diameter, variable-pitch propeller was also installed.

Wedell-Williams Model 45 front

The Model 45 with its R-1340 engine installed. Note the bumps on the cowling that provided clearance for the engine’s rocker covers. The engines used in the Model 45 and Model 44 (No. 44) racer were interchangeable.

The Model 45 made its race debut at the Pan American Air Races held during the dedication of Shushan Airport (now New Orleans Lakefront Airport) in February 1934. Wedell flew the Model 45 to a new speed record over a 100 km (62 mi) course, averaging 264.703 mph (425.998 km/h), with the fastest lap over 266 mph (428 km/h). Wedell reported that he flew the distance at less than full power.

After the record run, Wedell-Williams Air Service began work to prepare their aircraft for the 1934 Bendix and Thompson Trophy Races, respectively scheduled for 31 August and 4 September. But disaster struck on 24 June 1934; Jimmie Wedell was killed when the de Havilland Gypsy Moth he was piloting crashed shortly after takeoff. Wedell was with a student pilot but had control of the aircraft. The student escaped with only minor injuries. The loss of head designer Jimmie Wedell was a major blow to Wedell-Williams Air Service, but the company continued to plan for the upcoming races.

Wedell-Williams Model 45 Jimmie

Jimmie Wedell stands by the Model 45. Note the doors for the retractable tail skid.

Experienced Wedell-Williams pilot John Worthen flew the Model 45 in the Bendix Trophy Race from Los Angles, California to Cleveland, Ohio. Worthen led the race, followed by Doug Davis flying Wedell-Williams Air Service’s other racer, a Model 44 (No. 44). Worthen, in the Model 45, had a comfortable lead when he became lost and overflew Cleveland by 100 miles (160 km). Worthen landed and refueled in Erie, Pennsylvania and then flew to Cleveland; he landed 36 minutes behind Davis. Had he not overflown Cleveland, Worthen and the Model 45 would have easily won the Bendix race; the trip to Erie added over 50 minutes to his total time. Even with the delay, the Model 45 had averaged 203.213 mph (327.040 km/h) in the Bendix Trophy Race.

In the Shell Speed Qualification heat (Group 3) for the Thompson Trophy Race, Worthen and the Model 45 placed third at 292.141 mph (470.156 km/h), coming in behind the Model 44 racers of Davis (No. 44) at 306.215 mph (492.805 km/h) and Roscoe Turner (No. 57) at 295.465 mph (475.505 km/h). In the Shell Speed Dash Unlimited race, Worthen and the Model 45 achieved 302.036 mph (486.080 km/h).

Wedell-Williams Model 45

The size and weight of the Wedell-Williams Model 45 was more suited for cross-country racing than pylon racing. It would have won the 1934 Bendix race had it not been for a navigation error. The Model 45 is barely an aviation footnote since it was flown fewer than two years and never won a major race.

The Wedell-Williams Air Service team decided that the Model 44 (No. 44) had the greatest potential for the Thompson Trophy Race. This decision was made because of some instability the Model 45 exhibited in the pylon turns—perhaps because the aircraft was not fully refined due to Wedell’s death. The team had been swapping the R-1340 and R-985 engines between racers for various events, and now the R-1340 engine was installed in the Model 44 for the Thompson Trophy Race. The Model 45 would not be competitive with the R-985 engine, and it was withdrawn from the race.

During the Thompson Trophy Race, Davis and the Model 44 were comfortably in the lead when he cut a pylon. He went back to circle the pylon when the aircraft either stalled or experienced a structural failure. The Model 44 smashed into the ground, killing Davis instantly. The shocked Wedell-Williams Air Service team disassembled the Model 45 and shipped it back to Paterson; it never flew again.

Wedell-Williams Air Service was never able recover because tragedies continued to plague the company. On 18 July 1935, Walter Wedell and his passenger were killed in a crash while flying in a Brewster Aristocrat. On 19 May 1936, Harry Williams and John Worthen were killed in a crash after the engine in their Beech Staggerwing quit shortly after takeoff.

Wedell-Williams Model 45 Cleveland side

The Model 45 at the National Air Races in Cleveland, Ohio in September 1934. The unfortunate death of Jimmie Wedell seemingly cut short the aircraft’s development, and the Model 45 never reached its true potential. Its predecessor, the Model 44, continued to race until 1939, the last year of the races until after World War II.

The Model 45 was donated to Louisiana State University in 1936, but what happened to it is not known. It was most likely scrapped at some point. A full-scale replica Model 45 is in the Wedell-Williams Aviation and Cypress Sawmill Museum in Patterson, Louisiana.

Early in 1934, the Army Air Corps expressed interest in the Model 45 design suitably modified into a military pursuit aircraft. Initially, the Wedell-Williams Air Service proposal was rejected, but a subsequent proposal was approved, and a contract was issued on 1 October 1935 for detailed design work. The Wedell-Williams Air Service fighter was designated XP-34. The XP-34 had a wingspan of 27 ft 9 in (8.5 m) and a length of 23 ft 6 in (7.2 m). The 4,250 lb (1,928 kg) aircraft was forecasted to have a top speed of 286 mph (460 km/h) with a 750 hp (559 kW) P&W R-1535 or 308 mph (496 km/h) with a 900 hp (671 kW) P&W R-1830. The design of the XP-34 progressed until the aircraft was cancelled after the death of Williams in 1936, by which time its performance had been surpassed by other fighters.

Wedell-Williams Model 45 replica

The Wedell-Williams Model 45 replica in the Wedell-Williams Aviation and Cypress Sawmill Museum in Patterson, Louisiana. (Steffen Kahl image via Flickr)

Sources:
Wedell-Williams Air Service by Robert S. Hirsch and Barbara H. Schultz (2001)
Aircraft of Air Racing’s Golden Age by Robert S. Hirsch and Ross N. Hirsch (2005)
The Golden Age of Air Racing Pre-1940 by S. H. Schmid and Truman C. Weaver (1963/1991)
They Flew the Bendix by Don Diggins (1965)
Racing Planes and Air Races 1909-1967 by Reed Kinert (1967/1969)
http://www.crt.state.la.us/louisiana-state-museum/online-exhibits/louisiana-aviation-since-1910/jimmie-and-walter-wedell/

Roscoe Turner Howard Bendix 1933

Air Racing Was Like This – by Roscoe Turner

Roscoe Turner

Roscoe Turner, ever the showman, with his impeccable custom uniform and well trimmed mustache. Turner once admitted that he did not like wearing his uniform but used it to stand out and get publicity wherever he went.

Roscoe Turner (29 September 1896 – 23 June 1970) was the preeminent aerial showman of the 1930s, and perhaps of all time. From 1929 to 1930, Turner set numerous cross-country speed records and won many air races. He was awarded the Harmon Trophy in 1933 and 1939 and the Henderson Trophy in 1933, 1938, and 1939. He won the Bendix Trophy in 1933 and the Thompson Trophy in 1934, 1938, and 1939. Turner also placed second in the MacRobertson International Air Race from London to Melbourne. To raise publicity while he was flying for the Gilmore Oil Company in the early 1930s, Turner adopted a lion cub and flew with him until he became too large. A lion’s head was the logo for the Gilmore Oil Company, and Turner named the cub Gilmore. Turner retired from air racing in 1939, but continued to be involved in aviation until his death, which, unlike for so many early aviators, was from natural causes.

The following was originally from the August 1956 edition of Pegasus, the Fairchild Engine and Airplane Corporation’s magazine.

Ten… Nine… Eight… Seven seconds, the clock on the dash panel says, ticking them off. And you sit there in the cramped cockpit and sweat. Waiting for the starter to drop the flag.

The tiny racing plane trembles. The propeller clatters. The skin throbs.

You’re in No. 2 position, next to the orange job with the taper wing, second from the end of the line. There are nine others, wing-tip to wing-tip, all rarin’ to go. Stinging, snorting little hornets.

And you’ve got to fly each one of them besides your own. Because you never know what the other guy is going to do.

Roscoe Turner Lockheed Vega 1929

Turner stands in front of the Nevada Airlines Lockheed Vega (NC7954) in which he set various cross-country speed records and flew in the 1929 Thompson Trophy Race.

This is the Thompson Trophy Race. The big one. The National Air Races. The one that really counts. Aviation’s “Kentucky Derby.” You’ve got to win. Everything you own is wrapped up in this trim and powerful little racer. Everything. Even your spare watch is in hock.

For 365 days, since the race last year, you’ve been getting the ship ready. Wings clipped to cut through the air faster. Engine souped up to get more power. One thousand two hundred horsepower in your lap and a feather in your tail. That’s what it amounts to. Enough to make any aeronautical engineer beat himself to death with his slide rule.

For what? For fame and glory and headlines and the prize money. So you can pay off your debts and come back next year.

Roscoe Turner Gilmore 1930

Turner poses with Gilmore the lion cub on the tail of the Gilmore Oil Company sponsored Lockheed Air Express in 1930. Turner made a custom parachute for the lion cub, and the pair flew together until the lion had grown too big (150 lb / 68 kg). Turner funded Gilmore’s care until the lion died in 1952. Gilmore was then stuffed and kept by Turner until he passed away in 1970. Gilmore is preserved and in storage at the National Air and Space Museum.

Check your instruments, fuel gauge. Pressure gauge. Oil temperature. Tachometer. Cylinder head temperatures. Glance at the chronometer. The clock has stopped. No, it’s still running.

Six… Five… Four… Why is a second a year? Tick, tick, tick, it sounds like the bong of Big Ben in your ears. Tension, nerves, fear. It drowns out the roar of the crowd.

The grandstand; a kaleidoscope of colors. It’ll be a blurred ribbon the next time you see it flash by.

See that black and yellow job down the line? Keep your eyes on him. He’s the guy to beat. Get out in front of him and try to stay there. No. 8, that’s him. Number Eight… Number Eight… Beat him… Beat him… The engine sings it. A battle cry. Remember what your mechanic said – “They’re ganging up on you. Look out! They’re going to try and box you in.” Just like they do at a horse race.

Roscoe Turner Gilmore Lockheed W-W 44 1932

Turner poses with his Gilmore Oil Company sponsored Lockheed Air Express (NR3057) and Wedell-Williams Model 44 (NR61Y) racer in 1932. At the time, the Model 44 had its original 535 hp (399 kW) Pratt & Whitney R-985 Wasp Jr engine. A replica of the racer is at the Wedell-Williams Aviation and Cypress Sawmill Museum in Patterson, Louisiana.

Three… Two… One second now to go!

Why won’t your feet be still? They’re jumping up and down on the rudder pedals. Dammit! You can’t stop them. And your hands? Sticky, trembling on the stick and throttle. Shaking like you’ve got the DTs. Goggles streaming with perspiration. Your clothes are soaked. They’re soggy. Itchy. Hell fever, that’s what you’ve got. Scared-to-hell fever. You always catch it right about now with one second to go. It’ll go away. As soon as… There’s the flag.

Slap the throttle. Werrummm! The ship leaps forward. Your feet stop jumping. Hands? Cold and steady. Now, crouched in the cockpit, this is your world. Nothing else matters. It’s up to you.

Faster, faster, faster, shooting across the field. Pull back on the stick. Not too fast. Easy does it. You’re free. The ship leaps forward again, like a shot from a gun. No more ground drag. Too much speed. You’ll rip the wings off if you don’t slow down the propeller.

Roscoe Turner Wedell-Williams 44 1933

Turner with his Wedell-Williams Model 44 in late 1933. An 800 hp (597 kW) Pratt & Whitney R-1340 Wasp Sr engine has now been installed in the racer.

Where are the others? Count ’em… one… two… three… they’re all up. Don’t get too close. One error and it’s curtains for both of you.

You’re no longer human. You’re a machine. Every move is timed to the split second… There’s the red roof. Pylon coming up. Left rudder. Left stick. Moving up. Wing down. You’re around. The straightaway. More throttle. The wind whistles in your ears.

Brown roof. Big tree. Another turn. Here comes the others. Who’s that on the left wing? He’s cutting in too close. You’ll get his prop wash on the next turn… Here it comes, boy… Hang on!

Too sharp. Take ’em wider next turn. Don’t try to cut so short. Let the other guy kill himself. You’re doing all right. There’s the grandstand again. Swoosh!

Pull off a strip of tape from the dashboard. That’s how you count the laps. Thirty laps. Thirty pieces of tape. Twenty-nine now… Check it the next time you go by the crowd. The guy will have the big numeral card out. It should read 28.

Roscoe Turner Boeing 247 1934

In 1934, this Boeing 247 (NR257Y) was flown by Turner, Clyde Pangborn, and Reeder Nichols to a second place finish in the Transport category of the MacRobertson Race, covering some 11,300 miles (18,200 km). The aircraft was borrowed from United Airlines and fitted with extra fuel tanks in the fuselage. After the race, it was returned to service by United. This aircraft is currently preserved in the National Air and Space Museum in Washington, DC.

Where is No. 8? You can’t see him. Red roof again… turn… straightaway… throttle… brown roof… big tree… pylon… The grandstand. Okay, it says 28.

There he is! Just ahead. You’re gaining on him. Faster, faster… Pour it on. Pray this thing will hold together… Red roof coming up… Try to cut it real short this time… Take the chance… Maybe you can get him on the turn… NOW… Wing down deep… Snap back… jerk… Shake, tremble, roar! But you made it. There’s nobody in front of you.

Instruments?… Oil pressure… Supercharger… Gas… Speed… Okay… If they only stay like that. Remember what happened last year- when the supercharger blew. It was only doing 2000 rpm then… Now it’s doing 3000. You improved it. But that much?

Pylon. Grandstand. Tape. Round and round going nowhere. Brown roof. Red roof. Big tree. Straightaway. Pylon. Zoom, zoom, zoom. Wing up. Wing down. Level off. More pylons. More trees, more roofs. It’s hot. Like an oven. Is something on fire? Glance around? No, don’t, you mustn’t. At this speed you can’t take your eyes off what’s coming up ahead… Grandstand… Tape… There’s one piece left. One more lap.

You’re still out in front. If you could only look back and catch that number card for a recheck. It was so blurred. Maybe you missed a pylon. Maybe they’ll disqualify you. No, not that, please. And let’er hang together another two minutes.

Roscoe Turner Howard Bendix 1933

Turner and Benny Howard shake hands as Vincent Bendix looks on after the 1935 Bendix Trophy Race. Turner finished 23 seconds behind Howard in the cross-country race. Turner’s Wedell-Williams Model 44 racer now had its final power plant, a 1,000 hp (746 kW) Pratt & Whitney R-1690 Hornet engine housed in a close-fitting cowling.

It’s over.

You won!

You’re shaking again. You can hardly control the ship after she’s on the ground. Your heart beats louder than the engine. Uniform soaked, sopping wet. Hands tremble. Knees buckle as you climb out to meet the reporters and photographers with a big, forced smile… Headache. Muscle ache. Exhaustion. Oh, for a great big soft bed.

Air racing is like that. It’s the toughest test of all on men and machines. I know. For ten years I was pushing pylons in the Thompson. For ten years I was smashing records across the country in the big Bendix Transcontinental. Three times winner of the Thompson, many times loser. But it gets in your blood, and it stays.

It’s the most dangerous profession in the world.

Roscoe Turner Turner-Laird 1938

Turner applies power to the 1,000 hp (746 kW) Pratt & Whitney R-1830 Twin Wasp engine in his Turner-Laird RT-14 Meteor racer (Race 29, NR263Y) at the start of the 1938 Thompson Trophy Race in Cleveland, Ohio. Beyond the Keith Rider R-3/Marcoux-Bromberg Special (Race 3) flown by Earl Ortman is Turner’s Wedell-Williams Model 44 (Race 25) flown by Joe Mackey. All of these aircraft are preserved: the Meteor is in the Steven F. Udvar-Hazy Center of the National Air and Space Museum; the Model 44 is part of the Crawford Auto-Aviation Collection in Cleveland, Ohio; the R-3 is in the New England Air Museum in Windsor Locks, Connecticut.

More on Roscoe Turner:
Roscoe Turner: Aviation’s Master Showman by Carroll V. Glines (1995)

Napier-Heston Racer front 3-4 2

Napier-Heston Racer

By William Pearce

Near the end of World War I, D. Napier & Son built one of the most outstanding aircraft engines of all time: the 12-cylinder Lion. Lion production continued through the 1920s and 1930s, and other Napier aircraft engines did not achieve a level of success anywhere near that of the Lion. In the 1930s, Major Frank Halford was the head aircraft engine designer at Napier and was working on H-type engines. Compared to contemporary aircraft engines, Halford’s new engines used a smaller cylinder bore and stroke and ran at a higher rpm. In the late 1930s, Halford’s latest engine was the Sabre—a sleeve valve engine with 24 cylinders of 5.0 in (127 mm) bore and 4.75 in (121 mm) stroke. The Sabre displaced 2,238 (36.7 L) and was capable of over 2,000 hp (1,491 kW) and speeds up to 4,000 rpm.

Napier-Heston Racer front 3-4

The Napier-Heston Racer’s sleek lines and wide-track undercarriage are apparent in this view of the aircraft taken at the Heston Airport.

Napier wanted a way to demonstrate their new aircraft engine to the world. In its earlier days, the Lion had powered aircraft used to set world speed records. Since 1937, the Germans had held the landplane 3 km (1.86 mi) world speed record at 379.38 mph (610.55 km/h), and since 1934, the Italians had held the absolute 3 km (1.86 mi) world speed record at 440.682 mph (709.209 km/h). Napier felt a specially designed aircraft powered by a Sabre engine would be capable of setting a new speed record at over 480 mph (772 km/h), beating both the Germans and Italians. Not only would this achievement be great marketing, it would also bring the record back to Britain and embarrass Hitler’s Germany and Mussolini’s Italy.

Under lead designer Arthur E. Hagg, Napier laid out its racer design in mid-1938. Hagg previously designed the de Havilland DH.91 Albatross transport, and the two aircraft share some family resemblance. The racer’s sole purpose was to break the 3 km (1.86 mi) world speed record, and it was not intended as a testbed for the Sabre engine. The British Air Ministry was unwilling to financially support the project, but Lord Nuffield (William Richard Morris) stepped forward to independently fund the construction of two aircraft. In addition, a number of vendors donated parts and services or offered them at cost. Since Napier did not have the resources to construct the racer, the Heston Aircraft Company was selected to build the aircraft in late 1938. The Heston team was led by George Cornwall. The association between Napier and Heston gave the aircraft its popular name: the Napier-Heston Racer. The aircraft is also known as the Nuffield-Napier-Heston Racer, the Heston J.5 High-Speed Aircraft, and the Heston Type 5 Racer.

Napier-Heston Racer rear 3-4

The Napier-Heston Racer was painted silver with dark blue registration letters. Many layers of aircraft dope were applied to the birch ply sheeting that made up the exterior of the aircraft; this created a surface free from even the most minor of imperfections.

To expedite construction, the Napier-Heston Racer was built almost entirely of wood. The wing spars were made from compregnated wood of multiple laminations bonded with resin under high pressure. The fuselage frame and stringers and wing ribs were made of spruce. The wings and fuselage were covered with birch ply sheets. Split flaps were incorporated into the wings. The control surfaces had aluminum alloy frames and were covered with fabric. A variable-ratio control system was designed for the elevator. This system kept the elevator movements small when the control stick was near the neutral position. As the control stick was moved farther from neutral, the relative elevator movement became greater. This system was employed so that very precise elevator movements could be achieved at high speeds.

The Napier-Heston Racer was fitted with one of the first six Sabre I prototype engines, but its boost was increased. The standard Sabre I engine produced 2,000 hp at 3,700 rpm, but the racer’s engine produced 2,450 hp (1,827 kW) at 3,800 rpm. The racer had a 10 ft 9 in (3.28 m) diameter, metal, three-blade, de Havilland constant-speed propeller. Wing root intakes led to the engine’s supercharger. A radiator was housed in a duct under the aircraft. The radiator’s upper and lower surfaces were sloped back and formed a deep V in the duct. After air passed through the radiator, it was expelled under the horizontal stabilizer on both sides of the tail. A channel above the radiator skimmed off the turbulent boundary layer, allowing it to bypass the radiator. The wide-track (14.8 ft / 4.5 m) main gear retracted fully into the wings, and a small tail skid was incorporated into the fixed fin of the tail. After many layers of aircraft dope were applied, the fit and finish of the racer was near perfection.

Napier-Heston Racer left

The rather small size of the Napier-Heston Racer is illustrated in this photo. The radiator’s intake duct can be seen under the aircraft, and its exit duct under the horizontal stabilizer. Note the bulges in the cowling to allow clearance for the Sabre’s cylinder banks.

Between the engine and fully enclosed cockpit was a 73 gallon (276 L) fuel tank. At full throttle, the aircraft’s endurance was only 18 minutes. The racer had a wingspan of 32 ft (9.75 m), a length of 24 ft 7 in (7.50 m), and a height of 11 ft 10 in (3.61 m). Its fully loaded weight was 7,200 lb (3,267 kg). All tolerances were kept to a minimum, and the racer was highly polished to remove any imperfections. The aluminum engine cowling had four bulges to allow clearance for the Sabre’s cylinder banks. The cowling sealed so tightly that small air vents were installed on the bulges to ensure that no combustible vapors built up in the engine compartment.

The first flight of a Sabre engine occurred on 31 May 1939. The engine was installed in a Fairey Battle flown by Chris Staniland. The Sabre-powered Battle had accumulated a number of hours before the special engine in the Napier-Heston Racer was first run on 6 December 1939. The racer was painted silver, with the registration of G-AFOK painted in dark blue. Taxi tests began on 12 March 1940 at Heston Airport. The engine and taxi test did not reveal any issues with control or engine cooling.

The Napier-Heston Racer’s first flight was delayed by weather but finally occurred on 12 June 1940. Squadron Leader G. L. G. Richmond was at the controls and flew the aircraft off from the 3,900 ft (1,189 m) grass field at Heston Airport. Reportedly, Richmond chose to make this flight without the canopy in place. Shortly after liftoff, the Sabre engine rapidly overheated, and Richmond tried to quickly bring the plane in for a landing. Sources disagree on exactly what happened next.

Napier-Heston Racer front

Two of the small engine compartment vents can just be seen on the upper bulges of the cowling. The exterior of the aircraft was kept as aerodynamically clean as possible.

Some sources state that Richmond was preoccupied with the emergency and was also being scalded by the overheated cooling system. They claim that he may have experienced some difficulty mastering control of the variable-ratio elevator, as he had almost touched down after a steep approach when the aircraft rose sharply back into the air and stalled. Other sources point out that the racer did not exhibit any cooling issues during the numerous ground engine runs and that Richmond was scalded when the coolant pipes burst as a result of the hard landing after the stall. They contend that the aircraft’s elevator became ineffective as a result of low speed and that it was possibly in the wings’ turbulent airflow during the steep pitch up before the stall. While some sources state the Sabre engine seized, others report the ignition was on and the engine was running but that Richmond did not advance the throttle because of its overheated state.

Richmond’s flight in the Napier-Heston Racer was only about six minutes, and he never retracted the gear. After liftoff, he immediately brought the aircraft around for landing. Richmond’s actions indicate he felt something was wrong very early on. While a burst cooling pipe would explain the cooling issues and Richmond’s scalding, and control issues with the elevator would explain the odd altitude deviations in the aircraft’s final moments, the exact issues and sequence of events may never be known.

Napier-Heston Racer front 3-4 2

The wing root intake scoops that provide air to the Sabre engine can clearly be seen in this photo. Two three-into-one exhaust manifolds on each side of the racer collected the Sabre’s exhaust gases.

The end result was that the Napier-Heston Racer stalled about 30 ft (9 m) above the grass runway and hit the ground hard. The impact broke the landing gear, the left wing, and the rear fuselage just behind the cockpit. Fortunately, Richmond was able to walk away from the wreck. With the war against Germany underway, no attempt was made to repair the Napier-Heston Racer. The racer’s Sabre engine was not badly damaged. It was rebuilt and installed in a production Hawker Typhoon that was used during the war. Although the second racer, registered as G-AFOL, was around 60% complete, it was never finished. The Napier-Heston Racer project had cost Lord Nuffield £50,000 to £100,000.

Between the time the Napier-Heston Racer was conceived and its first flight, Germany had increased the absolute world speed record to 469.221 mph (755.138 km/h). However, the Chief Technician and Aerodynamicist at Heston Aircraft, R. A. Clare, had estimated that the Napier-Heston Racer could achieve a maximum of 508 mph (818 km/h) over the 3 km (1.86 mi) course. While the true capabilities of the racer will never be known, attempts have been made to create a flying replica. Due to the high cost of such a project and the extreme rarity of Sabre engines, for now, a Napier-Heston Racer replica remains just a dream.

Napier-Heston Racer right side

The Napier-Heston Racer ready to fly at the Heston Airport. It is unfortunate that the aircraft never had a chance to demonstrate its true potential.

Sources:
– “The Napier-Heston Racer” by Bill Gunston Aeroplane Monthly (June 1976)
– “Napier-Heston Racer postscript” Aeroplane Monthly (August 1976)
– “A Co-operative Challenger” Flight (15 April 1943)
– “The Heston Napier Monoplane” by H. J. Cooper The Aero Modeller (August 1943)
By Precision Into Power by Alan Vessey (2007)