Category Archives: Air Racing and Records

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)

Curtiss XF6C-6 Page Navy Racer 18-08-1930

Curtiss XF6C-6 Page Navy Racer

By William Pearce

After World War I, it was clear that aircraft were vehicles with great potential, and not just playthings for the rich or eccentric. A rivalry built up between the United States Marine Corps, Navy, Army, and civilians as they each explored aviation in the 1920s. The military branches competed with each other in various races, with floatplanes switching to wheels for land-based races and wheeled aircraft switching to floats for sea-based races.

Curtiss XF6C-6 Page Navy Racer

The Curtiss XF6C-6 Page Navy Racer created for the 1930 Thompson Trophy Race.

US Marine Corps Captain Arthur H. Page flew his float-equipped Curtiss F6C-3 racer to victory in the Curtiss Marine Trophy Race on 31 May 1930, besting the rest of the field, which consisted entirely of Navy pilots. The F6C-3 was a member of the Curtiss Hawk family of biplane fighter aircraft, which had been steadily developed since the first Hawk was built for the Army in 1923. The F6C-3 had a fuselage and tail made of welded steel tubing and covered with fabric. The wings had a spruce structure and were fabric covered. Page’s F6C-3 (serial A-7147) had been cleaned up aerodynamically to achieve every bit of speed possible, and it averaged a race-record 164.08 mph (264.06 km/h).

Page knew he would need more speed from the F6C-3 if he were to have any chance in the inaugural Thompson Trophy Race, which would be held on 1 September 1930 during the National Air Races. In the 1929 National Air Races, civilian Doug Davis in the privately-built Travel Air “Mystery Ship” beat both the Army and Navy Hawk entries when he averaged 194.9 mph (313.7 km/h) over the course of the race. Page wanted to avenge this humiliating defeat and set a new standard of speed in the process. Page won the support of the Navy Bureau of Aeronautics, and Curtiss went to work in June 1930 to turn the F6C-3 (serial A-7147) into a pure air racer. This was the same aircraft in which Page won the Curtiss Marine Trophy Race.

Curtiss F6C-3 Marine Race Page

The Curtiss F6C-3 Hawk that Arthur Page flew to victory in the 1930 Curtiss Marine Trophy Race. For that race, the radiator intake was modified, and the radiator housing was faired back to the tail. The fuel filler cap and pilot’s headrest were also faired to improve the aircraft’s aerodynamics. This aircraft was extensively modified into the XF6C-6 racer.

The modifications made to the F6C-3 were so extensive that the aircraft was redesignated XF6C-6. With the exception of the tail, the XF6C-6 bore no resemblance to the F6C-3. The 450 hp (336 kW) Curtiss D-12 engine was removed and replaced by a supercharged 750 hp (559 kW) Curtiss Conqueror engine. The Conqueror had a 5-1/8 in. (130 mm) bore and a 6-11/32 in (161 mm) stroke. The engine’s total displacement was 1,570 cu in (25.7 L), and it turned an 8 ft (2.4 m), two-blade, steel, ground-adjustable propeller.

The aircraft’s lower wing was removed, and the upper wing was moved back several inches. The now-parasol wing was mounted to the fuselage on streamlined struts. The wing had a duralumin leading edge, and brass surface radiators made up most of its upper and lower surfaces. Coolant was taken from the engine and flowed through pipes installed in the front wing struts. The coolant then flowed into header tanks along the wing’s leading edge and through the surface radiators. At the rear of the wing, the coolant was collected and flowed back to the engine via pipes that ran through the rear struts.

Curtiss XF6C-6 Page Navy Racer 18-08-1930

The completed Curtiss XF6C-6 on 18 August 1930. Even though it is the same aircraft, the modifications have made it unrecognizable from its F6C-3 origins.

The wing radiators enabled the chin radiator to be discarded, and a very streamlined aluminum engine cowling was fitted over the Conqueror engine. The landing gear was housed in aerodynamic wheel pants and attached to the fuselage by a single streamlined strut. The XF6C-6’s cockpit had metal panels on each side and was partially enclosed by a cushioned cover positioned over the pilot’s head. The panels hinged down, and the cover hinged to the rear for pilot entry and exit. The aircraft’s fuselage was aerodynamically cleaned up and recovered.

The XF6C-6 racer is often referred to as the “Page Racer” or “Navy Page Racer.” The aircraft had a polished navy blue fuselage and lower wing surface, and the upper wing surface was yellow. The exposed brass of the surface radiators was polished. The aircraft had a wingspan of 31 ft 6 in (9.6 m), a length of 23 ft 0 in (7.0 m), and a height of 8 ft 11 in (2.7 m). The XF6C-6 had an empty weight of 2,600 lb (1,179 kg) and a loaded weight of 3,130 lb (1,420 kg). Its range was 270 mi (435 km). The XF6C-6 had a cruising speed of 200 mph (322 km/h) and an estimated top speed of 250 mph (402 km/h).

Curtiss XF6C-6 Page Navy Racer cockpit

This image of the XF6C-6 racer shows the hinged cockpit sides and cover. The aircraft has its Thompson Trophy Race number (27) applied, and no carburetor scoop is visible. Note the exposed wheels.

Construction for the XF6C-6 was rapid, and the aircraft was completed by mid-August. The initial flight testing went well, but some signs of flutter were encountered at high speeds. Originally, a louvered panel on top of the engine cowling supplied air to the engine’s carburetor. A raised scoop replaced the louvers before the Thompson Race. However, some sources indicate the scoop was discarded and the louvered panel was reinstalled for the actual race.

The aircraft made its public debut for the Thompson Trophy Races held at the Curtiss-Reynolds airport (later Naval Air Station Glenview and now a shopping center) south of Chicago, Illinois. Captain Page in the XF6C-6 was the only military entrant in the field of seven. The XF6C-6 was larger than the other Thompson Trophy racers, but it was also more powerful.

Page was the first airborne, followed by the other racers at 10 second intervals. By the time the last racer took off, Page had almost completed his first lap of the five mile (8 km) circuit. The XF6C-6 was obviously much faster than the other racers; the only question was whether or not it would last the 20 laps. By the third lap, Page began lapping the slower aircraft. Page turned lap after lap at well over 200 mph (322 km/h), and the XF6C-6 went on to lap the entire field.

Curtiss XF6C-6 Page Navy Racer rear scoop

This image shows the Curtiss XF6C-6 racer again with its race number, but the carburetor scoop is in place. Also visible is the hand crank (and its shadow) used to start the engine. Note how the aircraft’s seams have been taped over to reduce drag.

On the 17th lap, Page went high and turned inside the course as he neared the home pylon. The XF6C-6 never straightened from the turn; it smashed into the ground as the 75,000 spectators looked on. Page survived the crash and was taken to a hospital where he died from his injuries later that night. Fellow race pilot Jimmy Haizlip, who had just been lapped by Page, noted the XF6C-6’s propeller was barely turning before the ground impact. In addition, the ignition switch was found in the “Off” position. It is believed that Page had been slowly overcome by carbon monoxide fumes from the exhaust that built up in the tight cockpit. Although too late, he realized the situation and shut off the engine in an attempt to get fresh air. He then turned inside the course to seek a safe landing but became incapacitated and crashed. Unfortunately, carbon monoxide poisoning was a fairly common occurrence in early aviation, and Page was one of many aviators who succumbed to exhaust fumes in the cockpit.

The XF6C-6 had turned each lap between 207 and 219 mph (333 and 352 km/h) before the crash (some sources state the average speed was 219 mph / 352 km/h). Speed Holman in the Laid Solution went on to win the race at 201.91 mph (324.94 km/h). With the death of Captain Page, American military aircraft were no longer entered in air races until after World War II. Even then, civilian and military racers participated separately (primarily because of the military’s switch to jet aircraft).

Curtiss XF6C-6 Page Navy Racer front scoop

The XF6C-6 during an engine run-up. This image provides a good view of the carburetor scoop and taped seams. The bulges on top of the wing are expansion tanks for the surface radiators.

Sources:
Curtiss Aircraft 1907-1947 by Peter M. Bowers (1979/1987)
Racing Planes & Air Races 1909-1967 by Reed Kinert (1967)
– “Captain Page and the 1930 Thompson Trophy Race” by Jimmy Halzip The Golden Age of Air Racing (1963/1991)
Thompson Trophy Racers by Rodger Huntington (1989)
http://1000aircraftphotos.com/Contributions/Shumaker/9130.htm
https://www.mca-marines.org/leatherneck/1930/07/marine-wins-curtiss-trophy

FIAT AS8 V-16 side

FIAT AS.8 Engine and CMASA CS.15 Racer

By William Pearce

Since 10 April 1933, Italy had enjoyed ownership of the 3 km absolute world speed record for aircraft. Warrant Officer Francesco Agello set the record at 423.824 mph (682.078 km/h) in the Macchi-Castodi MC.72 seaplane built for the Schneider Trophy Contest. The MC.72 was powered by a 24-cyllinder FIAT AS.6 engine. Agello went on to raise the record to 440.682 mph (709.209 km/h) on 23 October 1934 in another MC.72.

FIAT AS8 V-16 side

Side view of the FIAT AS.8 V-16 engine specifically designed for the CMASA CS.15 racer.

However, Germany captured the world speed record on 30 March 1939, when Hans Dieterle flew 463.919 mph (746.606 km/h) in the Heinkel He 100 (V8). Germany raised the record a month later on 26 April 1939, when Fritz Wendel traveled 469.221 mph (755.138 km/h) in the Messerschmitt Me 209 (V1).

Even before Dieterle’s record flight, the Italians had considered building an aircraft specifically for a new record attempt. FIAT, with the support of the Italian government, wanted to win the record back and had initiated an aircraft and engine design that was somewhat finalized before Wendel’s record flight. The new record aircraft was designed and built by Costruzioni Meccaniche Aeronautiche SA (CMASA), a FIAT subsidiary in Pisa. The engine would be designed and built at FIAT’s headquarters in Turin.

FIAT AS8 rear

A rear view of the FIAT AS.8 showing the valley between the engine’s banks. The small manifolds on each bank are to take the cooling water from the cylinders. They are installed backward in this photo; the outlet should be at the engine’s rear. The long intake manifold is reminiscent of the even-longer manifold used on the AS.6. The large port in the manifold elbow, seen just above the carburetor, is a relief valve to prevent over pressurization of the manifold (perhaps in the event of a backfire—a major issue in the early development of the AS.6).

The aircraft was designed by Manlio Stiavelli and was known as the Corsa (meaning Race) Stiavelli 15, or just CS.15. Lucio Lazzarino, an engineer at CMASA, analyzed and tested various aspects of the CS.15 design. The CS.15 was a small, mid-wing, all-metal aircraft with a very low frontal area. Its 29.5 ft (9.0 m) monospar wing had conventional flaps and ailerons. The cockpit was situated far aft on the 29.2 ft (8.91 m) fuselage and was faired into the long tail.

To keep the wing thin and the fuselage narrow, the main wheels of the CS.15 folded toward each other before retracting aft into the fuselage. The CS.15’s fuel tank was situated behind the engine, in front of the cockpit, and above the main landing gear well. Fuel capacity was very limited, and the CS.15 was only meant to have enough endurance to capture the speed record—about 30 minutes of flight time. The estimated empty weight of the CS.15 was 4,213 lb (1,910) kg, and its total weight was 5,000 lb (2,270 kg).

To power the CS.15, Antonio Fessia and Carlo Bona laid out the AS.8 (Aviazione Spinto 8) engine design at FIAT. The AS.8 was a completely new design but had many common elements with the AS.6 engine used in the MC.72. The AS.6 was designed by Tranquillo Zerbi, and Fessia had taken over Zerbi’s position at FIAT when he passed away on 10 March 1939. The AS.8 was a liquid-cooled engine with cylinders very similar to the AS.6’s, utilizing two intake and two exhaust valves actuated by dual overhead camshafts. The AS.6 and AS.8 shared the same 5.51 in (140 mm) stroke, but the AS.8’s bore was increased .08 in (2 mm) to 5.51 in (140 mm). Reportedly, the AS.6 and AS.8 used the same connecting rods and both engines were started with compressed air.

FIAT AS8 front

This view displays the four magnetos of the FIAT AS.8 just above the propeller gear reduction. Note the the air distribution valves driven by the exhaust camshafts for starting the engine. The outlet of the water pumps can be seen in the forward position, which differs from the first image on this page.

The AS.8 was unusual in many ways. Its two banks of eight individual cylinders were set at 45 degrees. The 16 cylinders gave a total displacement of 2,104 cu in (34.5 L). The cylinders had a 6.5 to 1 compression ratio. The single-stage supercharger was geared to the rear of the engine and provided pressurized air to the cylinders via a long intake manifold between the cylinder banks. The carburetors were mounted above the supercharger. Unlike the AS.6, which used independent coaxial propellers, the AS.8 featured contra-rotating propellers geared to the front of the engine at a 0.60:1 reduction. Two sets of two-blade propellers 7.2 ft (2.2 m) in diameter could convert the AS.8’s power into thrust for the CS.15. The engine weighed 1,742 lb (790 kg).

Nine main bearings were used to support the long crankshaft and to alleviate torsional vibrations. In addition, drives for the camshafts, magnetos, and water pumps were mounted at the front of the engine. Each cylinder bank had two magnetos to fire the two spark plugs per cylinder. The distributor valve for the air starter was driven from the front of the exhaust camshaft for each cylinder bank. The exhaust gases of the AS.8 were utilized to add propulsive thrust through specially designed exhaust stacks on each cylinder.

FIAT AS8 bank

A detailed view of the AS.8’s right cylinder bank. Each cylinder had one spark plug on the outside of the engine and one in the Vee. The pipe next to the spark plug is for the air starter. The manifold at the bottom fed cool water into the cylinder jacket. (Emanuele image via Flickr)

For cooling, pressurized water was drawn into a pump on each side of the engine, near its front. A manifold delivered the water to each cylinder on the outside of the bank. The water then flowed through the cylinders and exited their top into another manifold situated in the Vee of the engine. The heated water, still under pressure, was taken back to the CS.15’s tail, where it was depressurized and allowed to boil. The steam then flowed through the CS.15’s wings, where 80% of their surface area was used to cool the steam and allow it to condense back into water. The water was then re-pressurized and fed back to the engine. Engine oil was also cooled by surface cooling in the rear and tail of the aircraft.

CMASA CS15

A three-view drawing of the CMASA CS.15 racer. Note the thin wings, minimal frontal area, and main gear retraction.

By early 1940, full-scale mockups of various CS.15 components were built and the construction of the CS.15 was underway. Wind tunnel tests indicated the CS.15 would reach a speed of 528 mph (850 km/h). The AS.8 engine was running on the test stand at this time. During these tests, the AS.8 achieved an output of 2,500 hp (1,864 kW), but the engine was rated at 2,250 hp (1,678 kW) at 3,200 rpm. The engine accumulated tens of hours running on the test stand and encountered few, if any, major failures. It is not known how many AS.8 engines were built, but the number is thought to be very small. The AS.8 was also the starting point of another V-16 engine, the FIAT A.38.

After Italy entered World War II in June 1940, progress on the CS.15 and AS.8 continued but at a much reduced pace. The CS.15 was damaged in various air raids, and it was further wrecked by the Germans as they exited Italy in late 1943. Some believe that whatever remained of the CS.15 was taken to Germany, as the aircraft essentially disappeared. As for the AS.8 engine, one example survived the war and is on display (or in storage) at the Centro Storico Fiat (Fiat Historic Center) in Turin, Italy.

The AS.8 achieved a power output greater than 1 hp/cu in and 1 hp/lb—accomplishments that were sought after by engine designers around the world.

Sources:
MC 72 & Coppa Schneider Vol. 2 by Igino Coggi (1984)
Aeronuatica Militare Museo Storico Catalogo Motori by Oscar Marchi (1980)
World Speed Record Aircraft by Ferdinand Kasmann (1990)
Italian Civil and Military Aircraft 1930-1945 by Jonathan W. Thompson (1963)

savoia-marchetti s64 take off

Savoia-Marchetti S.64 and S.64 bis

By William Pearce

Inspired by Charles Lindbergh’s New York to Paris transatlantic flight of 3,600 miles (5,800 km) in May 1927, Italian pilot Arturo Ferrarin discussed with Alessandro Marchetti the possibility of building an aircraft to set non-stop distance records. Ferrarin was an experienced long distance flyer, having flown from Rome to Tokyo in 1920. Marchetti was the chief designer for Savoia-Marchetti and had complete control of the aircraft’s design and configuration. What emerged from Marchetti’s drafting table was the S.64. The Italian Air Ministry supported the project as a way to demonstrate the capabilities of Italian aviation to the world; two S.64 aircraft were ordered in late 1927.

savoia-marchetti s64 take off

The Savoia-Marchetti S.64 taking off from Montecelio. The retractable radiator can be seen under the wing and just behind the fuselage nacelle.

The Savoia-Marchetti S.64 was an aircraft of a rather unorthodox configuration yet similar to Marchetti’s earlier flying boat design, the S.55. Unlike the twin-hulled S.55 flying boat, the S.64 was a landplane. The S.64 consisted of a large, thick cantilever wing. A fuselage nacelle was blended into the center of the wing. The nacelle protruded below the wing and extended beyond its leading edge, but it was part of the wing’s structure. The pilot and copilot sat side-by-side and were provided with a rest area for long-distance flights. The wing and fuselage nacelle were made of wood and skinned with plywood. The wing housed 27 fuel tanks that combined to accommodate 1,717 gallons (6,500 L) of fuel.

Two frame booms made of duralumin extended behind the wing and supported the S.64’s slab horizontal stabilizer. Attached to the center of the horizontal stabilizer was the vertical stabilizer and rudder. Large control surfaces were attached to the trailing edge of both the horizontal and vertical stabilizers. Reportedly, the incidence of the horizontal and vertical stabilizers could be adjusted to trim the aircraft. The fixed main gear was faired and was suspended via struts under the wing. A tail skid was attached to the end of each boom.

savoia-marchetti s64 ferrarin del prete

Arturo Ferrarin, Carlo Del Prete, and the S.64.

A single FIAT A.22T V-12 engine was supported on struts above the wing. The FIAT A.22T was liquid-cooled and had a 5.3 in (135 mm) bore and 6.3 in (160 mm) stroke. The engine displaced 1,677 cu in (27.5 L) and produced 550 hp (410 kW). With the exception of its valve covers, the engine was encased in a streamlined cowl. At the very front of the cowl was a large oil tank for the engine. The pusher engine turned a two-blade wooden propeller with a streamlined, pointed spinner. Coolant from the engine traveled down the supporting struts into a radiator under the rear of the wing. The semi-retractable radiator could be extended below the wing for increased airflow.

The S.64 had a 70.5 ft (21.5 m) wingspan and was 34.1 ft (10.4 m) long. The aircraft had an empty weight of 5,291 lb (2,400 kg). Its useful load was 10,141 lb (4,600 kg), resulting in a maximum weight of 15,432 lb (7,000 kg)—nearly three times its empty weight. Its top speed was 146 mph (235 km/h), and cruise speed was around 100 mph (160 km/h). Takeoff speed with a heavy load was 93 mph (150 km/h). The S.64’s maximum range was estimated as 7,146 miles (11,500 km).

savoia-marchetti s64 Brazil

Brazilians assist the S.64 after it landed on the beach near Touros.

The first S.64, registered as I-SAAV, was first flown on 3 April 1928 at Cameri airfield in northern Italy by Alessandro Passeleva. The aircraft was then flown by Arturo Ferrarin and Carlo Del Prete, two men who would become very experienced in the S.64. Initial flight tests revealed the aircraft had a high takeoff speed that necessitated a smooth runway. On 18 April, Ferrarin flew the S.64 to Aeroporto Alfredo Barbieri in Montecelio, near Rome, where a special 4,265 ft (1,300 m) runway had been prepared. The beginning of the runway was paved and had a 6.5 percent grade to aid the aircraft’s initial acceleration. The rest of the runway had a 0.56 percent grade and was unpaved. Flight testing continued with progressively larger fuel loads, and a larger 9.8 ft (3.0 m) diameter propeller was fitted

On 31 May, Ferrarin and Del Prete took off with 921 gallons (3,486 L) of fuel in an attempt to set a new closed circuit distance record. The circuit was from Casale dei Prati in Montecelio to the tower at Torre Flavia (west to the coast) then south to the lighthouse at Anzio (by the coast) and back to Montecelio. After 58 hours and 34 minutes, Ferrarin and Del Prete landed at Montecelio on 2 June after traveling 4,763.82 miles (7,666.62 km) at an average speed of 86.48 mph (139.18 km/h). The S.64, with Ferrarin and Del Prete, had set new records for endurance, distance, and speed over a 5,000 km course. The S.64 beat the endurance record set by Americans Edward Stinson and George Haldeman, who flew for 53 hours and 35 minutes in a Stinson Detroiter aircraft in late March 1928.

savoia-marchetti s64 bis

A side view of the S.64 bis illustrating the duralumin booms that attached the tail to the rest of the aircraft.

The S.64 was then prepared for its next record flight—a straight-line flight of over 5,800 miles (9,300 km) from Montecelio to Rio de Janerio, Brazil. However, that plan was changed on account of high temperatures in Montecelio that would have necessitated a longer takeoff run. The runway at Montecelio had already been extended by 1,312 ft (400 m); its length was now 5,577 ft (1,700 m), but that would not be enough. The new destination was Bahia (now Salvador), Brazil, some 5,280 miles (8,500 km) away. The shorter flight allowed the fuel load to be reduced by 370 lb (168 kg), from 8,377 lb (3,800 kg) to 8,007 lb (3,632 kg).

On the evening of 3 July, Ferrarin and Del Prete departed Montecelio and headed southwest. The S.64 traveled toward Gibraltar and then headed down the coast of Africa and out across the Atlantic. On the afternoon of 5 July, Ferrarin and Del Prete crossed the Brazilian coastline, only to discover thick fog below. After searching in vain for a landing strip, they went back to the coast and set the S.64 down on the beach near Touros, Brazil. Landing in the sand damaged the S.64’s landing gear and fuselage. Not accounting for the distance flown looking for a landing strip, the S.64 set a new straight-line distance record of 4,466.58 miles (7,188.26 km). The flight was 49 hours and 15 minutes. Later, the S.64 was taken by ship to Rio de Janerio and donated to Brazil. (Unfortunately, Del Prete died in Brazil on 16 August 1928 from injuries suffered in the crash of another aircraft. A monument honoring Del Prete and the S.64’s flight was built in the Praça Carlo Del Prete in Laranjeiras, Rio – Rio de Janeiro, Brazil.)

savoia-marchetti s64 bis flight

The S.64 bis in flight showing the similar engine, wing, and boom configuration to the S.55.

Later in July after the S.64’s flight to Brazil, the Germans took the S.64’s endurance record with Johann Risztics and Wilhelm Zimmermann flying for 65 hours and 25 minutes in a Junkers W 33. Italy wanted the record back, and so the second S.64 was built. Finished in early 1929, the aircraft was designated S.64 bis to indicate changes made from the first S.64. The S.64 bis had a longer windscreen and a variable-pitch metal propeller.

Umberto Maddalena and Fausto Cecconi were selected to fly the S.64 bis, registered as I-SAAT. While flight testing was delayed in late 1929 because of bad weather, the French pilots Dieudonné Costes and Paul Codos took the S.64’s distance record. Flying in a Breguet 19 in mid-December, Costes and Codos traveled 4,989.26 miles (8029.44 km). Now the challenge was to set new endurance and distance records, and the S.64 bis would not disappoint.

savoia-marchetti s64 bis landing

The Savoia-Marchetti S.64 bis coming in for a landing.

On 30 May 1930, Maddalena and Cecconi took off from Montecelio in the S.64 bis and followed the same closed circuit course that the S.64 had traveled. Landing on 2 June (the second anniversary of Ferrarin and Del Prete’s flight), Maddalena and Cecconi and the S.64 bis were the new endurance and distance record holders. Their 67 hour, 13 minute, and 55 second flight had covered 5,088.28 miles (8,188.80 km).

Unfortunately the S.64 bis would set no additional records. On 19 March 1931, Maddalena and Cecconi and radio operator Giuseppe Da Monte embarked on a flight from Cinisello (near Milan) to Montecelio. About halfway into their flight, near Pisa, a failure occurred and the S.64 bis crashed into the sea off Calambrone. It is believed that the FIAT’s crankshaft broke, allowing the propeller to cut into the wing and fuselage nacelle of the S.64 bis. However, a definitive cause was never found. Tragically, Maddalena, Cecconi, and Da Monte were killed in the crash.

Carlo Del Prete memorial

The Carlo Del Prete memorial in Rio de Janeiro, Brazil. A sculpture of the S.64 flies above a stature of Carlo Del Prete as he stands before a plaque detailing the record flight. (Silvio Cezar Scremin image)

Sources:
Aeroplani S.I.A.I. 1915-1930 by Giorgio Bignozzi and Roberto Gentilli (1982)
SIAI Pagine Di Storia (1976)
Italian Civil and Military Aircraft 1930-45 by Jonathan W. Thompson (1963)
Jane’s All the World’s Aircraft 1931 by C. G. Grey (1931)
“The Rome—Brazil Non-Stop Flight” Flight (12 July 1929)
“Well-known Italian Pilots Killed” Flight (27 March 1931)
“The Accident to the S.64” Flight (3 April 1931)
http://archive.is/cNtFo
http://en.wikipedia.org/wiki/Savoia-Marchetti_S.64

Navy-Wright NW-1 Pulitzer

Navy-Wright NW-1 and NW-2 Racers

By William Pearce

Wright Aeronautical designed the T-2 engine in 1921 as a possible replacement for the Liberty V-12 engine and with the interest of the United States Navy. Like the Liberty, the Wight T-2 was a liquid-cooled V-12 engine. It also shared the same engine mount locations as the Liberty so that a T-2 could be installed in place of a Liberty. In the summer of 1922, the Navy saw an opportunity to test the 600 hp (447 kW), 1,948 cu in (31.9 L) T-2 engine and also create an air racer to compete in the upcoming Pulitzer Air Race.

Navy-Wright NW-1 Pulitzer

The Navy-Wright NW-1 (A-6543) with race number 9 at Selfridge Field, Michigan for the 1923 Pulitzer Race. Note that the engine cowling covers the engine cylinder banks. The image illustrates the limited ground clearance of the wheel fairings.

Commander Jerome C. Hunsaker, head of the Navy Bureau of Aeronautics Design Section, designed the T-2-powered racer known as the Navy-Wright NW-1. Two examples were ordered (A-6543 and A-6544), and Wright built the aircraft at Long Island City, New York in a plant rented from the Chance Vought Company. The aircraft was constructed under a fair degree of secrecy, with few details being leaked to the press. Because of the lack of information, the press dubbed the aircraft the Mystery Racer.

The NW-1 was a sesquiplane with the large upper wing situated about mid-height on the fuselage and the much smaller, lower wing in line with the main gear. The main gear was covered with close fitting fairings with little ground clearance. Two Lamblin radiators for engine cooling were located under the streamlined fuselage and above the main gear. The fuselage had a steel tube frame and was metal-covered in front of the cockpit, the rest of the fuselage was fabric-covered. The upper wing was plywood-covered back to the rear spar. The rest of the wing, including the ailerons, was fabric-covered. The lower wing was entirely plywood-covered. The NW-1 was a large racer with a wingspan of 30 ft 6 in (9.3 m), a length of 24 ft (7.3 m), and a height of 11 ft (3.4 m). The aircraft weighed 2,480 lb (1,125 kg) empty and 3,000 lb (1,361 kg) gross. The Wright T-2 engine turned a 9 ft (2.74 m), two-blade, wooden propeller.

Navy-Wright NW-1 Pulitzer rear

This rear view of the NW-1 clearly shows the difference in span of the sesquiplane’s wings. Note the Lamblin radiator supported by the gear struts.

The NW-1 was designed and built in three months. This tight schedule combined with engine delays meant only the first aircraft (A-6543) would be completed in time for the Pulitzer Race. Even so, there was no time to test fly the aircraft. Once the Wright T-2 engine (second production engine made) was installed, the NW-1 was crated and shipped to Selfridge Field, Michigan for the Pulitzer Race. Upon arrival, the NW-1 was prepared for its first flight. On 11 October 1922, three days before the Pulitzer Race, Lt. Lawson H. Sanderson took the NW-1 for its first flight. Sanderson was also the pilot selected to fly the NW-1 in the Pulitzer Race. During the 30 minute flight, the aircraft was clocked at 209 mph (336 km/h). Back on the ground, Sanderson reported that the aircraft had good flying characteristics and that there were no issues.

On the day of the Pulitzer Race, 14 October 1922, the crew had to clear a path on the grass field to make sure no irregularities in the ground would interfere with the NW-1’s very low wheel fairings. Sanderson got the aircraft aloft and entered the course. After 150 km (93 mi) of the 250 km (155 mi) race, the NW-1 was in fifth place and averaging 186 mph (299 km/h). However, the oil temperature had risen to the upper limit of the gauge. The short test flight had not revealed that the aircraft’s oil cooler was insufficient. Sanderson found the gauge disconcerting and temporally “fixed” the issue by covering it with his handkerchief. Of course, this did nothing to alter fate.

Navy-Wright A-6544

The second Navy-Wright NW-1 (A-6544). Note that the engine cowling no longer covered the engine cylinder banks and that the wheels are no longer covered by fairings.

A few minutes later, while over Lake St. Clair, Sanderson could smell the burning oil of the overheating engine and saw smoke trailing behind his racer. He pulled off the course and headed for the closest landfall. As he approached Gaulker Point, he saw the shore crowded with spectators. About then, the T-2 engine finally seized, giving Sanderson very few options. He headed for shallow water, and when he made contact with the water’s surface, the NW-1 quickly flipped over. Sanderson was now underwater, in the cockpit, and stuck in mud; he literally had to dig his way out. Remarkably, Sanderson emerged unharmed, but the NW-1 was destroyed.

Back in Long Island City, the second NW-1 (A-6544) was completed on 22 December 1922. This aircraft differed slightly from the earlier version. It had a modified engine cowling to aid cooling, and the wheel fairings were omitted. Because of the modifications, some sources say that the aircraft’s designation was changed to NW-2 at this time, but most others continued to refer to the aircraft as the NW-1. Obviously confident in the aircraft, Sanderson made the first flight, followed by a number of others, at Mitchel Field, New York. He reported that the oil cooling issue had improved but would still be a problem with warmer weather. He recorded a speed of 186 mph (299 km/h) with the engine at only 1,700 rpm.

Navy-Wright NW-2 rear

NW-2 (A-6544) after conversion to a seaplane with two full-span wings. Note the two-blade propeller, the wing radiators, and ventral fin.

Sometime after January 1923, A-6544 was taken to Wright’s factory in Paterson, New Jersey. Here, the aircraft underwent a major conversion to a seaplane and unquestionably became NW-2. The plan was to use the NW-2 in the Schneider Trophy Race held at Cowes, Isle of Wight, United Kingdom in September.

Both of the original wings were removed and two full-span wings were installed, converting the aircraft into a proper biplane. Two floats replaced the landing gear, and surface wing radiators replaced the Lamblins. The aircraft’s tail and rudder were enlarged and a ventral extension was added. When the NW-2 emerged in July 1923, it was the most powerful seaplane in the world. The NW-2 had a wingspan of 28 ft (8.5 m), a length of 28 ft 4 in (8.6 m), and a height of 11 ft 7 in (3.5 m). The aircraft weighed 3,565 lb (1,617 kg) empty and 4,447 lb (2,017 kg) gross.

Lt. Adolphus W. Gorton chose to fly the NW-2 for the Schneider Race and was also the only one to fly the aircraft during testing. The NW-2 was shipped to the Naval Aircraft Factory on the Delaware River near Philadelphia, Pennsylvania for testing. The first flight following the conversion occurred on 23 July 1923. Gorton reported that the aircraft was tail-heavy and created excessive spray while on the water. At the time, the NW-2 had a large, 8 ft 6 in (2.59 m) diameter wooden propeller. Adjustments to the NW-2 were made, including replacing the two-blade propeller with a metal, three-blade, 7 ft 6 in (2.29 m) diameter unit.

Navy-Wright NW-2

The NW-2 with race number 5 at the Isle of Wight and ready for the Schneider race. Note the three-blade propeller.

Test flights continued, and on 9 August 1923, Gorton was clocked at over 180.8 mph (291 km/h). On 18 August, Gorton, the NW-2, and the rest of the US Schneider team left for England on the SS Leviathan. After talking to the pilots of the Curtiss CR-3 racers also competing in the Schneider Trophy Race, Gorton realized that the NW-2 did not have the speed needed to win. As a result, the team decided to run the Wright T-2 engine at 2,250 rpm.

Gorton took the NW-2 up for a test flight and was clocked at an unofficial 204 mph (328 km/h). Everything had gone well on the flight. On 24 September 1923, Gorton took the NW-2 up again to get more familiar with the Schneider course. After 20 minutes of flight, while at a high-speed and a low-level, the Wright T-2 engine exploded, with parts flying in all directions. The NW-2 crashed into the waters of the Solent, flipped over and tossed Gorton out in the process. Unharmed, Gorton clung to pieces of wreckage until a boat rescued him. Like the NW-1, the NW-2 was completely destroyed after crashing into water. The Curtiss CR-3 racers went on to finish first and second in the Schneider Trophy Race.

Navy-Wright NW-2 tow

The Navy-Wright NW-2 being towed before a test flight. Lt. Adolphus W. Gorton can be seen in the middle of the boat.

Sources:
The Speed Seekers by Thomas G. Foxworth (1975/1989)
The Pulitzer Air Races by Michael Gough (2013)
Schneider Trophy Seaplanes and Flying Boats by Ralph Pegram (2012)
The Air Racers by Charles A. Mendenhall (1971/1994)
http://woodenpropeller.com/forumvB/showthread.php?t=3235&highlight=hartzell

Hispano-Suiza 18Sbr

Hispano-Suiza 18R and 18Sb Aircraft Engines

By William Pearce

In the spring of 1928, after not participating in the Schneider Trophy contest for several years, the French Ministère de l’Air* (Air Ministry) set its sights on the competition for 1929. Aircraft for the race were ordered from Bernard and Nieuport-Delage. To be competitive, a new engine of around 1,200 hp was needed. The Ministère de l’Air put out orders for such an engine to Gnome-Rhône, Hispano-Suiza, and Lorraine. Only Hispano-Suiza was up to the challenge and responded with a new engine, known as the 18R.

Hispano-Suiza 18Sbr Musée de l'Air et de l'Espace

Hispano-Suiza 18Sbr W-18 engine on display in the Musée de l’Air et de l’Espace in Le Bourget, France. The 18Sb was essentially a detuned 18R. Note the carburetors on the sides of the cylinder banks and that each carburetor feeds two cylinders. (Duch.seb image via Wikimedia Commons)

The 18-cylinder, liquid-cooled Hispano-Suiza 18R had three very wide cylinder banks that formed a “W” (or broad-arrow) engine. The monobloc, six-cylinder banks were spaced at 80 degrees and derived directly from the Hispano-Suiza 12Nb V-12 engine of 750 hp (560 kW). The cylinders retained the 5.91 in (150 mm) bore and 6.69 in (170 mm) stroke of the 12Nb, but the compression ratio was increased from 6.2:1 to 10:1. The 18R’s total displacement was 3,300 cu in (54.1 L). The two valves per cylinder were actuated by a single overhead camshaft driven at the rear of the 18R. Each cylinder had two spark plugs positioned perpendicular to the cylinder but on opposite sides from one another. The spark plugs were fired by magnetos at the rear of the engine.

The engine’s connecting rods were of the master/articulated type, with the master rod for the vertical cylinder bank and articulated rods for the side cylinder banks. To keep the engine light, the crankcase and other components were made of Elektron, a magnesium alloy developed in Germany during World War I. The 18R was available with or without a Farmen (bevel planetary) propeller gear reduction, which weighed 132 lb (60 kg). The engine’s overall weight was 1,190 lb (540 kg) without gear reduction and 1,323 (600 kg) with gear reduction. The engine was 64.7 in (1.64 m) long without gear reduction and 78.5 in (1.99 m) long with gear reduction. The 18R had a width of 52.4 in (1.33 m) and a height of 46.1 in (1.17 m).

Hispano-Suiza 18Sbr

Front view of a Hispano-Suiza 18Sbr. The tube on the front of each cylinder bank supplied oil to the overhead camshaft.

The 18R had a planned output of 1,680 hp (1,253 kW) at 2,400 rpm. However, developmental issues delayed the engine, and neither it nor the aircraft it was to power were ready for the 1929 Schneider contest. The first 18R engine, a geared drive version, was delivered to Nieuport in October 1929, a month after the contest.

The Schneider contest racer from Nieuport-Delage was known as the NiD-450, and two were ordered. It was a low wing, wire-braced seaplane of conventional layout. When installed in the NiD-450, the 18R was limited to 1,200 hp (895 kW) at 2,000 rpm. For the NiD-450, the engine’s nine carburetors were placed between the cylinder banks. This limited the interference between the fairings for the side cylinder banks and the wing. Although the engine was installed and test-run in the NiD-450 in 1929, the aircraft did not undergo tests until February 1930. The first flight was made by Sadi Lecointe at the end of April. The NiD-450 was damaged in June when the engine cowling came free while in flight and struck the aircraft. Once repaired, the aircraft was damaged again in July when it crashed while taking off.

A further development of the NiD-450 built for possible use in the 1931 Schneider contest was the NiD-650. In fact, the second NiD-450 was finished as the first NiD-650, and the first NiD-450 was rebuilt and modified, becoming the second NiD-650. Still powered by the Hispano-Suiza 18R, the first NiD-650 was delivered on 11 February 1931. Lecointe made the first flight on 12 March, but the aircraft’s handling was not good. Modifications and test flights continued, but the aircraft crashed on 22 July. The pilot, Ferdinand Lesne, was not harmed. The second NiD-650 was flown on 31 August by Lecointe. The aircraft performance was less than what was needed for the Schneider contest, and there was not enough time for any improvement.

Nieuport-Delage NiD-650

Both Nieuport-Delage NiD-450s became NiD-650s, an example of which is seen here. Note how the side cylinder bank was housed in its own fairing, completely separate of the low-mounted wing. For the NiD-450/650, all nine of the 18R’s carburetors were installed between the cylinder banks.

The Schneider contest racer from Bernard was known as the HV120. Two were built, and the HV120 had a layout similar to the NiD-450. The HV120 used a direct drive 18R engine and was ready for tests in early 1930, long after the 1929 contest. For the HV120, the carburetors for the engine’s lower cylinder banks were placed under the banks. This allowed the side cylinder banks to be faired into the wings. Antoine Paillard undertook the aircraft’s testing and made the first flight on 25 March 1930. The highest recorded speed for the HV120 was 317 mph (510 km/h), far below the competition. Modifications were made for the HV120’s possible use in the 1931 contest, but by this time, the aircraft was mainly used for flight training while newer racers were prepared. Unfortunately, the first HV120 was destroyed when it crashed on 30 August 1931, killing its pilot, Georges Bougault, who was the leader of the French Schneider team. The second HV120 was ready for flight, but little effort was made to prepare it for the Schneider contest.

The Hispano-Suiza 18R had absolutely no success with the Schneider Trophy contest. The engine was delayed, but there were many issues with the racing aircraft as well. In an attempt to recoup its loss and make something out of the 18R, Hispano-Suiza detuned the engine for commercial use. Known as the 18Sb, the engine had its compression returned to 6.2, was limited to 2,000 rpm, and had an aluminum crankcase. With the changes, the engine had a respectable max output of 1,125 hp (840 kW) and a normal output of 1,000 hp (745 kW). With gear reduction the engine was known as the 18Sbr and weighed 1,300 lb (590 kg). Without rear reduction the engine was known as the 18Sb and weighed 1,138 lb (516 kg). Other dimensions were the same as the 18R, except the 18Sb’s height was slightly reduced to 45.3 in (1.15 m).

Bernard HV140

Bernard HV140 had the side banks of the Hispano-Suiza 18R faired into the wings. It is because of this that the carburetors for the lower cylinder banks were mounted under the banks.

Although many projects were proposed to use the 18Sb, few were actually built. One aircraft that probably should have remained a project was the Ford 14-AT (some say 14-A), the last of the Ford trimotors. Developed in relative secrecy, the blunt nosed Ford 14-A was an all metal monoplane built in 1932 by the Stout Metal Airplane Division of the Ford Motor Company. The aircraft had a wingspan of 110 ft (33.5 m), length of 80 ft (24.4 m), and was built to carry 40 passengers. Two 715 hp (533 kW) Hispano-Suiza 12Nc V-12 engines were buried in the wings, and a single 18Sbr W-18 was mounted on a pylon atop the aircraft.

The 14-AT tried numerous times to take flight, none of which brought success. Originally designed for Pratt & Whitney air-cooled radial engines (Henry Ford made the engine change), the heavy 14-AT would not leave the ground and was damaged in an attempt to pry it free from earth. Reportedly, Edsel Ford ordered the 14-AT quietly scrapped in 1933, without ever making a public appearance.

One Hispano-Suiza 18Sbr engine is preserved at the Musée de l’Air et de l’Espace (Air & Space Museum) in Le Bourget, France.

Ford 14-AT

The very large and unsuccessful Ford 14-AT. Note the four-blade propellers on the wings and the three-blade propeller for the high-mounted 18Sbr.

*Technically, France’s 1929 Schneider efforts were started by the Ministère de la Marine (Ministry of the Navy). The Ministère de l’Air was not established until October 1928 and subsequently took over the Schneider efforts and other aviation projects.

Sources:
Schneider Trophy Seaplanes and Flying Boats by Ralph Pegram (2012)
Hispano Suiza in Aeronautics by Manuel Lage (2004)
Aerosphere 1939 by Glenn Angle (1940)
Jane’s All the World’s Aircraft 1931 – 1933 by C.G. Grey
Beyond the Model T: The Other Ventures of Henry Ford by Ford Bryan (1997)

Kawasaki Ki-78 (KEN III)

By William Pearce

In the 1930s, Japanese aviation began to make strides toward closing the technological gap with the Western World. In 1938, the Aeronautical Research Institute of the University of Tokyo, led by Shoroku Wada, began a high-speed aircraft research program. Gathering data on high-speed flight was the primary objective, but it was felt that an attempt on the 3 km absolute world speed record was an obtainable goal.

The nearly complete and unpainted high-speed research aircraft, the Kawasaki Ki-78. Note the radiator housing on the fuselage side.

The aircraft project was known as KEN III (for Kensan III or Research III) and incorporated numerous advanced features new to Japanese aircraft. Approval was given for the aircraft’s development and a full-scale wooden mockup was finished in May 1941. Because of the outbreak of World War II, the project was taken over by the Imperial Japanese Army and designated Ki-78. A production contract for two prototypes was awarded to Kawasaki, under the direction of Isamu Imashi. Construction of the first prototype began in September 1941 at Kawasaki’s plant at Gifu Air Field.

The Ki-78 was an all-metal, low wing monoplane of conventional layout. The small streamlined fuselage was made as narrow as possible and was 26 ft 7 in (8.1 m) long. The wings possessed a laminar flow airfoil with a span of 26 ft 3 in (8 m) and an area of 118.4 sq ft (11 sq m). To reduce landing speed and improve low-speed handling, the wings incorporated drooping ailerons along with a combination of Fowler and split flaps, which was a first for a Japanese aircraft. When the Fowler flaps were deployed, the split flaps opened simultaneously to a similar extent. When the flaps were fully deployed, the ailerons automatically drooped down 10 degrees.

Factory fresh and unpainted view of the Ki-78. The aircraft is missing its outer gear doors and there is no horn-balance on the elevator.

Power for the Ki-78 was provided by an imported Daimler-Benz DB 601A inverted V-12 engine driving a three-blade metal propeller. The engine was not a Kawasaki Ha-40, a licensed copy of the DB 601. The DB 601 had a 5.91 in (150 mm) bore and 6.30 in stroke (160 mm), giving a total displacement of 2,070 cu in (33.9 L). It produced 1,175 hp (876 kW) at 2,500 rpm. The engine was modified by Kawasaki with the addition of a water-methanol injection system (another Japanese first) to boot the power output to 1,550 hp (1,156 kW) for short periods. The Ki-78 carried 66 gal (250 L) of fuel and 16 gal (60 L) of water-methanol.

The freshly-painted Ki-78 running-up its DB 601A engine. Note the hinge in the outer gear door to account for extension of the gear strut.

The freshly-painted Ki-78 running-up its DB 601A engine. Note the hinge in the outer gear door to account for extension of the gear strut.

Engine cooling was provided by two radiators: one mounted on each side of the rear fuselage. The radiators had a wide air inlet protruding slightly out from the fuselage. Airflow through each radiator was controlled by an actuated exit door. In addition, within the fuselage a small 60 hp (45 kW) turbine drove a fan to further assist cooling. The aircraft stood 10 ft 7/8 in (3.07 m) tall and weighed 4,255 lb (1,930 kg) empty.

The Ki-78 first flew on 26 December 1942 and was found to be extremely difficult to fly at low speeds and had poor stall characteristics. The aircraft was heavier than the design estimates, which increased the wing loading. Even with the special flaps and drooping ailerons, takeoff and landing speeds were both high at 127 mph (205 km/h) and 106 mph (170 km/h) respectively. In addition, elevator flutter was experienced at the relatively low speed of 395 mph (635 km/h) but was subsequently cured by fitting a horn-balance to the elevator.

Rear view of the Kawasaki Ki-78 as found by American troops after the war. Note the flat tailwheel and missing cockpit glass, flight instruments, and starboard tire. This view also displays the radiator exit door and elevator horn-balance.

High-speed flight tests were started in April 1943, and during the Ki-78’s 31st flight on 27 December, the aircraft achieved its maximum speed of 434.7 mph (699.6 km/h) at 11,572 ft (3,527 m). This was considerably less than the program’s speed goal of 528 mph (850 km/h). A study showed that extensive airframe modifications were needed to improve the Ki-78 flight performance. Consequently, the project was officially terminated after the aircraft’s 32nd flight on 11 January 1944. Only one prototype was built.

The unique Ki-78 survived the war but was crushed by American forces at Gifu Air Field in 1945.

The sole Ki-78 being crushed by American forces at Gifu Air Field, after the war, in 1945.

Sources:
World Speed Record Aircraft by Ferdinand Kasmann (1990)
Japanese Aircraft of the Pacific War by Rene Francillon (1970/2000)
General View of Japanese Military Aircraft in the Pacific War by Airview (1956)
http://forum.axishistory.com/viewtopic.php?t=32870
http://www.letletlet-warplanes.com/2008/06/04/the-kawasaki-ki-78-ken-iii-research-plane/

Bugatti 110P Racer top

Bugatti Model 100P Racer

By William Pearce

Ettore Bugatti was born in Milan, Italy on 15 September 1881. In 1909, he founded his own automobile company in Molsheim, in the Alsace region. The Alsace region was controlled by the German Empire until 1919, when control returned to France. The Bugatti race cars were incredibly successful in the 1920s and 1930s, collectively wining over 2,000 races. During that time period, Bugatti enjoyed seeing the small machines that bore his name defeat the larger and more powerful machines of his major rivals: the German vehicles from Mercedes-Benz and Auto Union.

Bugatti 110P Racer top

The elegant lines of the Bugatti 100P are well displayed in this image. (Hugh Conway Jr. image)

In 1936, Bugatti began to consider the possibility of building an aircraft around two straight eight-cylinder Bugatti T50B (Type 50B) engines, very similar to the engines that powered the Bugatti Grand Prix race cars. This aircraft would be used to make attempts on several speed records, most importantly, the 3 km world landplane speed record, then held by Howard Hughes in the Hughes H-1 Racer at 352.389 mph (567.115 km/h). Bugatti turned to Louis de Monge, a Belgian engineer, to help design the aircraft, known as the Bugatti Model 100P.

Bugatti 100P general arrangement drawing based off the original drawings by Louis de Monge. Note the arrangement of the power and cooling systems.

Before construction of the Bugatti 100P began, Germany demonstrated what if felt was its aerial superiority by setting a new 3 km world landplane speed record at 379.63 mph (610.95 km/h) in a Messerschmitt Bf 109 (V13) on 11 November 1937. Bugatti disliked Nazi-Germany and was very interested in beating their record. Bugatti and de Monge continued to develop the 100P for an attempt to capture the 3 km record from Germany.

The Bugatti 100P was one of the most beautiful aircraft ever built. With the exception of engine exhaust ports, the 25 ft 5 in (7.75 m) fuselage was completely smooth. The aircraft employed wood monocouque “sandwich” construction in which layers of balsa wood were glued and carved to achieve the desired aerodynamic shape. Hardwood rails and supports were set into the balsa wood to take concentrated loads at stress points, like engine mounts and the canopy. The airframe was then covered with tulipwood strips, which were then sanded and filled. Finally, the aircraft was covered with linen and doped. The Bugatti 100P stood 7 ft 4 in (2.23 m) tall and weighed 3,086 lb (1,400 kg).

The 100P had a 27 ft (8.235 m), one-piece wing that was slightly forward-swept. The wing had a single box spar that ran through the fuselage. The wing was constructed in the same fashion as the fuselage and housed the fully retractable and enclosed main gear. The wing featured a multi-purpose, self-adjusting flap system (U.S. patent 2,279,615). Both the upper and lower flap surfaces automatically moved up or down to suit the speed of the aircraft and the power setting (manifold pressure) of the engines. At high manifold pressure and very low airspeed, the flaps set themselves to a takeoff position. At low airspeed and low power, the flaps dropped into landing position, and the landing gear was automatically lowered. In a dive, the flaps pivoted apart to form air brakes.

Image of the nearly complete Bugatti 100P still under construction in Paris. The cooling-air inlet in the butterfly tail can be easily seen.

The Bugatti tail surfaces consisted of two butterfly units and a ventral fin at 120-degree angles (French patent 852,599). They were constructed with the same wood “sandwich” method used on the fuselage and wing. The tip of the ventral fin incorporated a retractable tail skid.  For cooling, air was scooped into ducts in the leading edges of the butterfly tail and ventral fin. The air was turned 180 degrees, flowed into a plenum chamber in the aft fuselage, and passed through a two section radiator (one section for each engine) located behind the rear engine. The now-heated air again turned 180 degrees and exited out the fuselage sides into a low pressure area behind the trailing edge of the wings. The high pressure at the intake and low pressure at the outlet created natural air circulation that required no fans or blowers (U.S. patent 2,268,183).

The two Bugatti T50B straight eight-cylinder engines were specially made for the 100P aircraft. The engine crankcases were made of magnesium to reduce weight, and each engine used a lightweight Roots-type supercharger feeding two downdraft carburetors. The T50B had a bore of 3.31 in (84 mm) and a stroke of 4.21 in (107 mm), giving a total displacement of 289 cu in (4.74 L). Twin-overhead camshafts actuated the two intake and two exhaust valves for each cylinder. The standard T50B race car engine produced 480 hp (358 kW) at 5,000 rpm. An output of 450 hp (336 kW) at 4,500 rpm is usually given for the 100P’s engines; however, de Monge stated the engines planned for the 100P were to produce 550 hp (410 kW) each. The engines were situated in tandem, behind the pilot. The front engine was canted to the right and drove a drive shaft that passed by the pilot’s right side. The rear engine was canted to the left and drove a drive shaft that passed by the pilot’s left side. The two shafts joined into a common reduction gearbox just beyond the pilot’s feet. The gearbox allowed each engine to drive a metal, two-blade, ground-adjustable Ratier propeller. Together, the two propeller sets made a coaxial contra-rotating unit. From the gearbox, the rear propeller shaft (driven by the front engine) was hollow, and the front shaft (driven by the rear engine) rotated inside it (U.S. patent 2,244,763).

Image of the two T50B engines in the Bugatti 100P while at the Ermeronville estate. Note the radiator at left , how the engines are canted within the fuselage, and how the exhaust ports on the front engine protrude through the fuselage.

Once the new design was finalized in 1938, construction of the 100P was begun at a high quality furniture factory in Paris. While construction proceeded, it was obvious that war would break out soon. France did not have any fighters that could match the performance of their German counterparts. The French Air Ministry felt the 100P could be developed into a light pursuit or reconnaissance fighter and awarded a contract to Bugatti in 1939. This fighter was to be equipped with at least one gun mounted in each wing, an oxygen system, and self-sealing fuel tanks. Most aspects of the fighter are unknown, but it is possible that it was larger than the 100P and incorporated 525 hp (391 kW) T50B engines installed side-by-side in the fuselage driving six-blade coaxial contra-rotating propellers with a 37-mm cannon firing through the propeller hub. Because of France’s surrender, the aircraft never progressed beyond the initial design phase.

The Bugatti 100P, finally in all its glory after being completely restored by the Experimental Aircraft Association. Note the fairing for the rear engine ‘s exhaust ports above the wing. (Hugh Conway Jr. image)

Bugatti’s contract included a bonus of 1 million francs if the 100P racer captured the world speed record which the Germans had raised to 463.919 mph (746.606 km/h) with a Heinkel He 100 (V8) on 30 March 1939 and raised again to 469.221 mph (755.138 km/h) with a Messerschmitt Me 209 (V1) on 26 April 1939. Bugatti and de Monge felt the 100P was capable of around 500 mph (800 km/h). In addition, a smaller version of the racer, known as the 110P, was planned; it featured a 5 ft (1.525 m) reduced wingspan of 22 ft (6.7 m). The 110P was to have the same engines as the 100P, but the top speed was estimated at 550 mph (885 km/h). However, other sources indicate these figures were very optimistic, and the expected performance was more around 400 mph (640 km/h) for the 100P and 475 mph (768 km/h) for the 110P.

The 100P was nearly complete when Germany invaded France. As the Germans closed in on Paris in June 1940, the Bugatti 100P and miscellaneous parts, presumably for the 110P, were removed from the furniture factory and loaded on a truck. The 100P was taken out into the country and hidden in a barn on Bugatti’s Ermeronville Castle estate 30 mi (50 km) northeast of Paris.

Bugatti 100P on display at the EAA AirVenture Museum in Oshkosh, Wisconsin. The cooling air exit slots on the left side of the aircraft can be seen on the wing trailing edge fillet. Also note the tail skid on the ventral fin.

Ettore Bugatti died on 21 August 1947 with the 100P still stashed away in Ermeronville. The aircraft was purchased by M. Serge Pozzoli in 1960 but remained in Ermeronville until 1970 when it was sold to Ray Jones, an expert Bugatti automobile restorer from the United States. Both Pozzoli and Jones offered the 100P to French museums but were turned down. Jones acquired the 100P with the intent to complete the aircraft; however, that goal could not be completed due to missing parts. Jones had the two Bugatti T50B engines removed from the airframe before everything was shipped to the United States. Dr. Peter Williamson purchased the airframe and moved it to Vintage Auto Restorations in Ridgefield, Connecticut in February 1971 to begin a lengthy restoration. Les and Don Lefferts worked on the project from 1975 to 1979. Louis de Monge was now living in the United States and assisted with some aspects of the restoration work before he passed away in 1977. In 1979, the unfinished 100P was donated to the Air Force Museum Foundation with the hope of having the restoration completed and the aircraft loaned to a museum for display. However, the aircraft sat until 1996 when it was donated to the Experimental Aircraft Association (EAA) in Oshkosh, Wisconsin and finally underwent a full restoration. The restored, but engineless, Bugatti 100P is currently on display at the EAA AirVenture Museum.

The original engines out of the Model 100P were reportedly not the final version of the engines intended for the actual speed record run. Both engines still exist and are installed in Bugatti automobiles. The front engine is installed in Ray Jones’ 1937 Type 59/50B R Grand Prix racer, and the rear engine is installed in Charles Dean’s 1935 Type 59/50B Grand Prix racer. Since January 2009, Scotty Wilson has led an international team, including Louis de Monge’s grand-nephew, Ladislas de Monge, to build a flying replica of the Bugatti 100P in Tulsa, Oklahoma. Piloted by Wilson, the Bugatti 100P replica flew for the first time on 19 August 2015. Tragically, Scotty Wilson was killed when the replica crashed during a test flight on 6 August 2016.

Bugatti 100P on display at the EAA AirVenture Museum in Oshkosh, Wisconsin. Simply one of the most beautiful aircraft ever built.

Sources:
The Bugatti 100P Record Plane by Jaap Horst (2013)
World Speed Record Aircraft by Ferdinand Kasmann (1990)
Airplane Racing by Don Berliner (2009)
The Classic Twin-Cam Engine by Griffith Borgeson (1979/2002)
http://www.bugattiaircraft.com/kalempa.htm by Alex Kalempa
http://www.airventuremuseum.org/collection/aircraft/2Bugatti Model 100 Racer.asp
http://www.airventuremuseum.org/collection/aircraft/2Bugatti Model 100 Racer Facts.asp
http://morlock68.pagesperso-orange.fr/bugatti.htm
http://bugatti100p.com/
http://en.wikipedia.org/wiki/Bugatti
http://kfor.com/2016/08/06/historic-replica-airplane-the-bugatti-100p-crashes-near-burns-flat-pilot-and-designer-scotty-wilson-dies/

FIAT AS.6 Aircraft Engine (for the MC.72)

By William Pearce

For the 1929 Schneider Trophy Contest, Italy fielded a number of different aircraft and engine combinations. The end result was that none of their entries were developed enough be victorious, and Britain won the contest for the second time in a row. If the British were to win the competition in 1931, the Schneider Contest would be over, and Britain would retain permanent possession of the Schneider Trophy.

Side view of the FIAT AS.6 illustrating the engine’s length. In the middle of the engine at bottom, two water pumps can clearly be seen with coolant lines feeding the individual cylinders. Right behind the propeller hubs, one of the front engine section’s magnetos can be seen. The small pipes leading from the middle of the engine toward the rear engine section and from right behind the front engine section’s cylinder bank and toward the front engine are for the air starter.

To prevent a British victory in 1931, Italy focused on developing one aircraft and one powerplant for its Schneider efforts. Macchi Aeronautica was chosen to develop the airframe, and with the design talents of Mario Castoldi, the Macchi-Castoldi 72 (MC.72) was born. FIAT was tasked with developing an engine to power the MC.72 and defeat the British. Time was short for FIAT because the MC.72 would be designed around the engine.

As the FIAT engine team, led by Tranquillo Zerbi, began to develop a new powerplant, they quickly realized that there was not enough time to start from scratch; the engine that was to power the MC.72 would have to start from an existing engine. FIAT’s best powerplant at the time was the 1,000 hp (746 kW) AS.5 (Aviazione Spinto) V-12 engine. This engine was used in one of Italy’s 1929 Schneider racers, the FIAT C.29. The Italian team knew the engine would need at least 2,300 hp (1,715 kW) to win the 1931 Schneider Contest and began developing a supercharger, increasing the engine’s compression, and incorporating other enhancements to attempt to achieve the desired power. But even early on, Zerbi knew the AS.5 engine could not develop the power needed to defeat the British.

While working on the enhanced AS.5, a proposal was made to mount two AS.5 engines back-to-back, creating a V-24 engine. FIAT moved forward with the concept and called it the AS.6, but it was not as simple as bolting two AS.5 engines together. The AS.5 engine sections were not coupled together. They shared a common magnesium crankcase and an induction manifold, and there was only one throttle linkage. Everything else (the ignition, coolant, and oil systems) was independent for each engine section.

Rear view of the FIAT AS.6 showing the two four-barrel carburetors feeding the supercharger. Directly below the supercharger are fuel pumps and the two magnetos for the rear engine section.

A 0.60 gear reduction for the propellers would be driven from the back of each AS.5 engine section (middle of the V-24 power plant). A drive shaft would be taken from the gear reduction of each engine. These drive shafts would travel through the Vee of the front engine and to the nose of the aircraft.  The rear engine drove a 69.96 in (1.77 m) shaft inside the front engine’s 52.52 in (1.334 m) shaft. Via the drive shaft, each engine drove one pair of propellers that together made a coaxial contra-rotating unit; the front engine drove the rear propeller, and the rear engine drove the front propeller. Coaxial contra-rotating propellers allowed for a blade short enough to avoid sea spray and also cancelled out the torque of the engine.

The rear engine section powered a supercharger that supplied 6.5 psi (0.45 bar) of air to both engine sections through a manifold approximately 88.58 in (2.25 m) long. The supercharger took 250 hp (186 kW) to run and spun at 17,000 rpm. The propeller pitch was ground adjustable. The front and rear propellers were adjusted to different pitches to compensate for the supercharger’s drain on the second engine section (front propeller) and efficiency differences between the first and second set of blades. The metal propellers were 8.5 ft (2.59 m) in diameter.

A detailed view inside the FIAT AS.6. The propeller gear reduction and drive shafts can clearly be seen. Note the individual cylinders on the far side of the engine and how the two crankcase sections are joined in the middle.

The FIAT AS.6 was a liquid-cooled, 60-degree, V-24 engine. It used individual steel cylinders, each with a 5.4 in (138 mm) bore and 5.5 in (140 mm) stroke, giving a total displacement of 3,067 cu in (50.256 L). The engine had a maximum compression ratio of 7 to 1. Four valves per cylinder were actuated by dual-overhead camshafts. The AS.6 was 132.48 in (3.365 m) long, 27.64 in (0.702 m) wide, 38.43 in (0.976 m) tall, and weighed 2,050 lb (930 kg). The engine was started by compressed air fed from a distribution pump located on the gear reduction housing. The rear engine section was started first.

Each inboard camshaft was driven from a gear parallel to and smaller than the propeller reduction gear. The outboard camshaft was geared to the inboard camshaft. Oil and water pumps were gear driven from the crankshaft. Each bank of each engine section had its own water pump. Ignition for each engine section was provided by two magnetos. The rear engine section’s magnetos were crankshaft driven and located below the supercharger. The front engine section’s magnetos were located on top of the engine, near the propellers, and driven from the outer (front engine’s) propeller shaft. Each cylinder had two spark plugs installed perpendicular to its axis: one located below the intake valves and the other below the exhaust valves.

Sectional view of the FIAT AS.6 illustrating the propeller drive shafts. Note the gear drive for the camshafts at top, the oil and water pumps at bottom, the front engine section’s magnetos at front, and the supercharger and rear engine section’s magnetos at rear.

During development, the AS.6 engine suffered many technical difficulties. Issues were encountered with spark plugs, ignition, coolant flow, fuel metering, induction, exhaust valves, connecting rods, and supercharger drive, to name a few. Much time was spent to resolve the issues. By April 1931, the engine completed a one hour run, producing 2,300 hp (1,715 kW).

The AS.6 engine was installed in the first of five MC.72 aircraft (MM 177 to MM 181), and flight trials began in the summer of 1931. Almost immediately, a new and very dangerous problem was discovered: while in flight, the engine would backfire at high power and high speed. The cause of this issue was a bit of a mystery because the engine ran perfectly on the ground but not during flight. Even with the engine’s difficulties, the aircraft had attained a speed of 375 mph (604 km/h). To demonstrate the backfire phenomenon, Capt. Giovanni Monti flew the MC.72 (MM 178) for FIAT and Macchi engineers on 2 August 1931. Sadly, a backfire ignited the volatile air/fuel mixture in the long induction manifold and caused it to explode. The MC.72 crashed into Lake Garda. Monti was killed in the crash.

FIAT AS.6 engine being test run in a MC.72.

With the Schneider Contest one month away and the cause of the backfiring still unknown, the decision was made to withdrawal the AS.6-powered MC.72 from the race. The British would make an uncontested flight for the Schneider Trophy and retain it permanently. But the Italians had decided to make an attempt on the absolute world speed record on 13 September 1931, the same day as the Schneider race. On 10 September, Lt. Stanislao Bellini was making a practice run to exceed 394 mph (634 km/h), the fastest the MC.72 had flown, when the aircraft (MM 180) flew straight into rising terrain. Debris found some distance from the impact site indicated that there had been an in-flight fire or explosion. Subsequently, the MC.72 was withdrawn from flight status.

The vision of what the AS.6 and MC.72 could have been continued to stir in the minds of various officials, and a new record attempt was planned. Believing the backfire issue was fuel related, the Italians wanted the help of Rod Banks: the Britain who developed the special fuel used for Rolls-Royce’s R Schneider engine. Banks was closely associated with the British Schneider effort but was not employed by Rolls-Royce or Supermarine. In 1932, the British sent Banks to see what could be done to improve the AS.6 engine.

Rear view of a preserved FIAT AS.6 engine at the Centro Storico Fiat in Turin, Italy. (Gianni image)

Banks arrived to find the AS.6 engine producing 2,400 hp (1,790 kW), but not reliably. A special sprint version of the engine had produced 2,850 hp (2,125 kW), but only for one minute. One of the issues Banks discovered was that the Italians had not fully accounted for the ram effect of having air forced into the induction by the forward speed of the aircraft. The AS.6 ran well on the ground, but the 400+ mph (640+ km/h) air being rammed into the intake caused a lean condition. This lean condition led to a backfire that ignited the air/fuel mixture in the long induction.

Banks knew how Rolls-Royce had dealt with this issue. Rolls-Royce had used a Kestrel engine to run a blower that supplied ram air for the R engine being tested. Banks had the Italians use a similar set-up that provided ram air at 435 mph (700 km/h) into the AS.6’s intake. The AS.6 engine was tuned under these conditions and no longer backfired. The sprint engine was able to produce 2,850 hp (2,125 kW) for an hour.

Warrant Officer Francesco Agello and the FIAT AS.6-powered MC.72 after setting the 3 km absolute world speed record at 440.682 mph (709.209 km/h) on October 23, 1934.

Late in 1932, the MC.72 took to the air once more; the AS.6 engine now produced a reliable 2,400 hp (1,790 kW). On 10 April 1933, Warrant Officer Francesco Agello set a 3 km absolute world speed record at 423.824 mph (682.078 km/h) in MM 177. On 8 October 1933, LtCol. Guglielmo Cassinelli captured the 100 km speed record at 391.072 mph (629.370 km/h). On 21 October, Capt. Pietro Scapinelli won the Blériot Cup in MM 179 for flying in excess of 600 km/h for over half an hour. His actual speed over the 30 minute run was 384.799 mph (619.274 km/h).

A year later, an AS.6 sprint engine was installed in the MC.72 (MM 181). This engine produced 3,100 hp (2,312 kW) at 3,300 rpm; 11.5 psi (0.79 bar) of boost was provided by the supercharger spinning at 19,000 rpm. On 23 October 1934, Agello was again at the controls and upped the 3 km record to 440.682 mph (709.209 km/h)—Agello was the fastest man on earth. This speed has never been surpassed by a piston-powered seaplane.

The record-setting MC.72 (MM 181) and an AS.6 engine are on display in the Museo Storico dell’Aeronautica Militare in Vigna di Valle, Italy. Another AS.6 engine is on display at the Centro Storico Fiat (Fiat Historic Center) in Turin, Italy.

The FIAT AS.6 displayed alongside the MC.72 (MM 181) at the Museo Storico dell’Aeronautica Militare in Vigna di Valle, Italy.

Sources:
The Schneider Trophy Story by Edward Eves (2001)
Schneider Trophy Seaplanes and Flying Boats by Ralph Pegram (2012)
Schneider Trophy Aircraft 1913-1931 by Derek James (1981)
Schneider Trophy Racers by Robert Hirsch (1993)
Jane’s All the World’s Aircraft 1935 by Grey and Bridgman (1935)
Italian High-Speed Airplane Engines NACA Technical Memorandum No. 944 by C. F. Bona (1935/1940) 17.7mb pdf
Technical Aspects of the Schneider Trophy and the World Speed Record for Seaplanes by Ermanno Bazzocchi (1971)
Idrocorsa Macchi by Apostolo and Cattaneo (2007)
I Kept No Diary by F.R. Banks (1978)

Bellanca 28-92 Trimotor

By William Pearce

The Bellanca 28-92 (construction no. 903) was developed by Giuseppe Bellanca in 1937 for Capt. Alexandru Papana. Papana was a Romanian Air Force pilot who planned to use the Bellanca on a long-distance good-will flight from New York to Bucharest. He named the aircraft Alba Iulia 1918 to commemorate the assembly of ethnic Romanian delegates who unified what is modern-day Romania at Alba Iulia, Transylvania in 1918. The aircraft carried the Romanian registration YR-AHA.

Alex Papana poses with the Bellanca 28-92. The Romanian registration can be seen on the wings but the name, “Alba Iulia 1918,” has yet to be applied. Note the propellers do not have spinners.

The Bellanca 28-92 was a low-wing, single-seat, trimotor design. The fuselage was of tubular steel construction and covered by aluminum back to the cockpit. Aft of the cockpit, the fuselage was covered with fabric. The wings and tail were plywood-covered, and the control surfaces were covered by fabric. The main undercarriage partially retracted into the rear of the wing engine nacelles, but the tailwheel did not retract.

Installed in each wing of the aircraft was a 250 hp (186 kW) Menasco C6S4 engine. The C6S4 Super Buccaneer was a direct drive, air-cooled, inverted, straight-six aircraft engine. The C6S4 was supercharged and displaced 544 cu in (8.9 L). Each C6S4 engine drove a 6 ft 6 in (1.98 m) diameter, two-blade, adjustable-pitch propeller.

The complete 28-92 with spinners and “Alba Iulia 1918” painted on the side. “YR” is painted on the tail, and the registration “YR-AHA” is repeated on the upper fuselage behind the cockpit..

A 420 hp (313 kW) Ranger SGV-770 engine was in the nose of the 28-92. The SGV-770 was an air-cooled, inverted, V-12 engine. The engine was supercharged, displaced 773 cu in (12.7 L), and had gear reduction for the 8 ft 3 in (2.51 m) diameter, two-blade, adjustable-pitch propeller.

All of the trimotor’s engines were hand cranked to start. The 28-92 had a fuel capacity of around 715 gallons (2,707 L). The aircraft had a span of 46 ft 4 in (14.1 m), a length of 28 ft 4 in (8.6 m), and weighed 4,700 lb (2,132 kg) empty. The 28-92 had a top speed of 285 mph (459 km/h) and a 3,000 mile (4,828 km) range at 250 mph (402 km/h) or a 4,160 mile (6,695 km) range at 200 mph (322 km/h). Landing speed was 75 mph (121 km/h).

Front view of the 28-92 trimotor illustrating the limited visibility from the cockpit while the aircraft was on the ground.

Papana was inexperienced with superchargers and inadvertently overboosted the engines during his first test flight in the trimotor. The incident led to a disagreement with Bellanca, and Papana cancelled his order for the aircraft. Since the 28-92 was complete and neither Papana nor the Romanian government paid for the aircraft, it remained at the Bellanca factory.

In 1938, Bellanca registered the aircraft in the United States as NX2433 and entered it in the Bendix Trophy cross-country race. Frank Cordova was the pilot for the race, and the trimotor flew as race number 99. Unfortunately, because of engine trouble, the aircraft did not finish the cross-country race. The Ranger engine in the nose quit, but Cordova continued to fly on the two Menasco engines for another 1,000 miles (1,609 km), landing in Bloomington, Illinois. A new rule for the 1938 races stated that no aircraft entered in the Bendix race could compete in the Thompson Trophy race, so the trimotor was returned to the Bellanca factory.

Bellanca 28-92 trimotor with Art Bussy at the controls for the 1939 Bendix race. The aircraft looked the same for the 1938 race except the race number was 99.

The 28-92 was again entered for the 1939 Bendix Trophy race, this time piloted by Art Bussy. Competing as race number 39, the aircraft finished second in the Los Angeles to Cleveland race with an average of 244.486 mph (393.462 km/h). Continuing on to New York, Bussy and the trimotor again finished second, averaging 231.951 mph (373.290 km/h) for the total distance from Los Angeles to New York.

Because of the start of World War II, all air races and record flights were put on hold. The Bellanca 28-92 trimotor was of little use during this time. The aircraft was eventually purchased by the Ecuadorian Air Force and served in South America from 1941 to 1945. Reportedly, the 28-92 was abandoned at a small airfield in Ecuador; a sad end for a unique aircraft.

Rear 3/4 view of the Bellanca 28-92 showing the aircraft’s clean lines.

*Sources disagree on what number the aircraft used for which year. Images reportedly from 1939 show number 39 on the fuselage, but it is possible that they are in error and race number 99 could have been used in 1939 and race number 39 used in 1938.

Sources:
Aircraft of Air Racing’s Golden Age by Robert and Ross Hirsh (2005)
The Air Racer by Charles Mendenhall (1994)
Aerosphere 1939 by Glenn Angle (1940)
Bellanca Specials 1925 – 1940 by Theo Wesselink (2015)
Jane’s all the World’s Aircraft 1938 by Grey and Bridgman (1938)