Category Archives: Post World War II

Sud-Est SE 580 cowling

Sud-Est (SNCASE) SE 580 Fighter

By William Pearce

The state-owned French aircraft manufacturer SNCAM (Société nationale des constructions aéronautiques du Midi or National Society of Aircraft Constructors South) was formed in March 1937 when the Dewoitine firm was nationalized. Many Dewoitine personnel, including the company’s founder, Émile Dewoitine, continued to work for SNCAM. As a result, aircraft designed and built at SNCAM continued to bear the Dewoitine name.

Sud-Est SE 580 model

Wind tunnel model of the Sud-Est SE 580 complete with contra-rotating propellers.

In 1940, SNCAM began studies of a new fighter aircraft. The aircraft was based on a continuing design evolution that started with the Dewoitine D.520 production fighter and progressed through the D.551/552 pre-production fighters. SNCAM’s new fighter design was designated M 580.

The M 580 aircraft was a tractor design with conventional undercarriage. However, the power plant was unique in that it utilized two Hispano-Suiza 12Z engines coupled in tandem and driving a contra-rotating propeller (similar to the Arsenal VB 10). The M 580 was designed by Robert Castello and Jacques Henrat, who had been very involved with previous Dewoitine fighter designs. Before much design work was completed, SNCAM was absorbed into SNCASE (Société nationale des constructions aéronautiques du Sud-Est or National Society of Aircraft Constructors Southeast) in late 1940.

With the SNCASE (often referred to as Sud-Est) takeover and the German occupation of France, the M 580 design languished during the war. Under Sud-Est, the aircraft was redesignated SE 580. Wind-tunnel tests were conducted in 1943, and the SE 580 design was changed to incorporate a new engine then under development. Gone was the tandem V-12 engine configuration, and in its place was a single 24-cylinder Hispano-Suiza 24Z engine. With much of France liberated in 1944, two SE 580 prototypes were ordered by the Ministère de l’Air (French Air Ministry). The Marine Nationale (French Navy) was interested in a navalized version designated SE 582 and ordered two prototypes in early 1945.

Sud-Est SE 580 HS 24Z

The SE 580 with open cowling revealing the 24-cylinder, 3,600 hp (2,685 kW) Hispano-Suiza 24Z engine.

Work on the SE 580 prototype was started first. The aircraft was of all-metal construction with fabric-covered control surfaces. The aircraft’s structure, especially the wings, followed basic Dewoitine design principals used in their earlier fighter aircraft. The SE 580 featured dive recovery flaps positioned under the wing and outside of the fully retractable main landing gear. Another unique feature was that the incidence of the aircraft’s horizontal stabilizer was adjustable.

The smooth flow of the aircraft’s fuselage was interrupted by a large hump behind the cockpit. This structure housed the scoop that directed air through a radiator positioned horizontally in the aircraft’s rear fuselage. Cooling air entered a large opening just behind the cockpit, traveled down through the radiator, and exited the fuselage via a ventral flap. The intake also incorporated a slot for boundary layer air bleed. The radiator’s location in the center of the aircraft offered some inherent protection that was further enhanced by rear armor plating to protect against enemy fire.

Three fuselage fuel tanks and one fuel tank in each wing held a total of 660 gallons (2,500 L). A drop tank under the fuselage held an additional 79 gallons (300 L) of fuel. The SE 580’s Hispano-Suiza 24Z engine was an H-24 that was forecasted to produce 3,600 hp (2,685 kW). The 24Z would turn an 11.5 ft (3.50 m) diameter, six-blade, contra-rotating propeller.

Sud-Est SE 580 front

The supercharger intakes and numerous exhaust stacks interrupt the otherwise clean lines of the SE 580’s fuselage. The dorsal radiator scoop created a large blind spot for the pilot. One must wonder how cleanly air would flow into the scoop after being disrupted by the canopy.

The SE 580’s armament was quite substantial and consisted of a 30 mm cannon mounted between the engine’s upper cylinder banks and firing through the propeller hub. Each wing housed two 20 mm cannons and four 7.5 mm (or three 12.7 mm) machine guns. A hardpoint under each wing could accommodate a 1,102 lb (500 kg) bomb. A photo reconnaissance version would accommodate a vertical camera in the central fuselage.

The SE 580 had a 52.0 ft (15.86 m) wingspan and was 42.7 ft (13.0 m) long. The aircraft had an empty weight of 11,228 lb (5,093 kg) and a gross weight of 17,919 lb (8,128 kg). The SE 580 had a top speed of 373 mph (600 km/h) at sea level and 465 mph (749 km/h) at 30,512 ft (9,300 m). Its landing speed was 88 mph (141 km/h). The SE 580 could climb to 19,685 ft (6,000 m) in just over six minutes and had a theoretical ceiling of 44,619 ft (13,600 m). The aircraft’s maximum range was 1,709 miles (2,750 km).

By 1946, construction of the first SE 580 prototype was well underway, and a Hispano-Suiza 24Z engine was installed in the airframe. Unfortunately, problems with the 24Z engine resulted in its cancellation. The Arsenal 24H was selected as the replacement engine. The 4,000 hp (2,983 kW) 24H was also a 24-cylinder engine in an “H” configuration but had many differences when compared to the 24Z. The 24H was heavier and had a different propeller location; it used a single rotation, 12.1 ft (3.70 m) diameter, five-blade propeller. These differences required numerous, complex changes to the SE 580. The longer propeller was located 5.12 in (130 mm) lower on the engine and required changes to the aircraft’s landing gear and wings to maintain acceptable ground clearance. Wind-tunnel tests indicated further wing changes would be needed and that the engine had to be moved forward. In light of all the required changes, budgetary cutbacks, Sud-Est’s preoccupation with other projects, and the emergence of jet aircraft, the SE 580 was cancelled in 1947.

Sud-Est 580 rear

This rear view of the SE 580 shows the large radiator housing behind the cockpit. Note the cooling air exit flap under the fuselage.

SE 582 development trailed behind that of the SE 580; the French Navy was more interested in the Sud-Ost SO.8000, and Sud-Est was more focused on the SE 580. Changes needed to navalize the aircraft included incorporating an arrestor hook and folding wings. Construction of the SE 582 was limited to components that were shared with the SE 580, but it does not appear that any substantial part of the SE 582 was ever completed. The SE 582 had the same basic specification as the SE 582, except it was 712 lb (323 kg) heavier, at a gross weight of 18,631 lb (8,451 kg).

When Sud-Est abandoned the SE 580/582, the possibility of SNCAC (Société nationale des constructions aéronautiques du Centre or National Society of Aircraft Constructors Center) taking over the projects was discussed. However, the status of aviation could not be changed—the SE 580 and 582 were outdated, and existing aircraft already matched their performance. The first SE 580 prototype was never completed.

Sud-Est SE 580 cowling

SE 580 was a large aircraft, and its predicted performance equaled, but not bettered, existing aircraft then in service. Lack of available information about the aircraft, combined with its unique configuration and engine have made the SE 580 a curiosity for many aviation enthusiasts.

Sources:
Les Avions de Combat Francais 1944-1960 I – Chasse-Assaut by Jean Cuny (1988)
Les Avions Dewoitine by Raymond Danel and Jean Cuny (1982)
http://www.secretprojects.co.uk/forum/index.php/topic,4110.0.html
http://www.aviationbanter.com/showthread.php?t=76826

CAC CA-15

Commonwealth Aircraft Corporation CA-15 ‘Kangaroo’

By William Pearce

In July 1942, Australia’s Commonwealth Aircraft Corporation (CAC) endeavored to improve the performance of their CA-12 (and CA-13) Boomerang fighter by installing a 1,700 hp (1,268 kW) Wright R-2600 engine in place of the 1,200 hp (895 kW) Pratt & Whitney (P&W) R-1830. However, the needed modifications to the Boomerang airframe proved to be too substantial. Since the need for an improved fighter was still pressing, CAC embarked to design an entirely new aircraft in November 1942. This new fighter aircraft was designated CA-15.

CAC CA-15 flight

The impressive Commonwealth Aircraft Corporation CA-15 on a test flight. Note the patches on the wings that replaced the gun ports for the .50 cal machine guns.

The preliminary design of the CAC CA-15 incorporated a Pratt & Whitney R-2800 engine, and the aircraft somewhat resembled a cross between a Boomerang and a Focke-Wulf Fw 190A. As the design evolved, the CA-15 changed to resemble a Hawker Tempest II with squared-off wings and tail, but with a General Electric (GE) C turbosupercharger installed in the rear fuselage, similar to the Republic P-47 Thunderbolt.

By mid-1943, a redesign was needed because the proposed power plant, the 2,000 hp (1,491 kW) R-2800-21, was not available. CAC selected the 2,200 hp (1,641 kW) R-2800-10W with a two-stage, two-speed supercharger as the new engine. With the engine change, the turbosupercharger was deleted, and a water-cooled intercooler was added in a large fairing under the engine. A geared cooling fan would help draw air in through the tight-fitting cowling. By December 1943, the R-2800-10W-powered CA-15 was estimated to have a maximum speed of 365 mph (587 km/h) at sea level, 436 mph (702 km/h) at 25,000 ft (7,620 m), and an initial climb rate of 4,200 fpm (21.3 m/s).

CAC CA-15 R-2800-21

The Pratt & Whitney R-2800-21-powered CA-15, with cutaway to show the fuselage fuel tank. The turbosupercharger installation in the rear fuselage is not visible. In this early 1943 drawing, the CA-15 has a passing resemblance to the Hawker Tempest II.

The switch to the R-2800-10W engine also shifted the CA-15’s area of maximum performance from high altitude to low/medium altitude. At the time, CAC had obtained a license to produce the North American P-51D Mustang as the CA-17 and CA-18; CA-17s would be assembled from parts, and CA-18s would be CAC-produced aircraft. Lawrence Wackett, CAC’s General Manager, envisioned the CA-17/CA-18 filling the high altitude fighter role and the CA-15 covering low and mid altitudes. From mid-1943, CAC was focused on CA-17 assembly and CA-18 production, and progress on the CA-15 slowed as a result.

With many components for the prototype CA-15 under construction, CAC was disappointed to learn in May 1944 that the R-2800-10W was no longer in production. CAC found a suitable replacement in the form of the 2,800 hp (2,088 kW) R-2800-57. With this engine change, the CA-15 was back to incorporating a turbosupercharger—now a GE CH-5 housed in a deeper fairing under the engine. The R-2800-57-powered CA-15 was estimated to have a maximum speed of 400 mph (644 km/h) at sea level, 480 mph (772 km/h) at 28,000 ft (8,534 m), and an initial climb rate of 5,700 fpm (29.0 m/s).

CAC CA-15 R-2800-57

A mid-1944 drawing of the CA-15 powered by a R-2800-57 engine. While the top view of the aircraft has not changed much, the bulky fairing under the engine has been added to house the intercooler and turbosupercharger.

By August 1944, the CA-15 prototype was around 50 percent complete. It was at this time that CAC was informed that supplies of the R-2800-57 could not be guaranteed. CAC again looked for an engine suitable for the CA-15 fighter. CAC found a new engine in the Griffon 125, then being developed by Rolls-Royce (R-R). The water-cooled Griffon 125 had a two-stage, three-speed supercharger and turned a single rotation propeller. The engine was capable of producing 2,440 hp (1,820 kW). A redesign of the CA-15 cowling was completed, and a scoop to house radiators for the engine coolant and oil was incorporated under the aircraft. With these changes, the CA-15 resembled a P-51D Mustang, but the resemblance was coincidental. The Griffon 125-powered CA-15 was estimated to have a maximum speed of 405 mph (652 km/h) at sea level, 467 mph (752 km/h) at 18,000 ft (5,487 m), and 495 mph (797 km/h) at 26,500 ft (8,077 m). The initial climb rate dropped slightly to 5,500 fpm (27.9 m/s).

Unfortunately, the Australian War Cabinet cancelled the CA-15 in September 1944. However, CAC continued work on the CA-15 at a reduced pace while it worked with the War Cabinet to reinstate the program. This was done in December, pending the approval of the Aircraft Advisory Committee, which followed in February 1945.

Work on the CA-15 now continued at a quicker pace, but engine issues surfaced again. R-R would not be able to provide a Griffon 125 until late 1945 at the earliest (but probably later). The CA-15 was ready for its engine, and CAC did not want to wait. As a substitute, two 2,035 hp (1,517 kW) Griffon 61s were loaned to CAC, the first being shipped in April 1945. The Griffon 61 had a two-stage, two-speed supercharger. As the CA-15 neared completion in December 1945, R-R informed CAC that the Griffon 125 would not be produced. The CA-15 used the Griffon 61 as its final engine, and the aircraft was completed in early 1946.

CAC CA-15

The completed CA-15 with its Griffon 61 engine bore a striking resemblance to the P-51D Mustang. However, the aircraft’s general layout changed little from the early 1943 drawing completed before CAC obtained a license for P-51 (CA-17/CA-18) production. Note the recessed engine exhaust stacks for improved aerodynamics.

The CA-15 was an all-metal aircraft of stressed-skin construction. The flaps and fully retractable gear were hydraulically operated. Various offensive armament combinations were considered, including four 20 mm cannons with 140 rpg, but six .50 cal machines guns were ultimately fitted with 250 rpg (various sources, including CAC documents, list 260, 280, or 290 rpg). The guns were not installed until a few months after the aircraft’s first flight. Underwing provisions existed for two 1,000 lb (454 kg) bombs or two 120 gal (100 imp gal / 454 L) drop tanks or 10 rockets.

In its final form, the CA-15 had a 36 ft (11 m) wingspan and was 36 ft 3 in (11 m) long. The aircraft’s internal fuel capacity was 312 gal (260 imp gal / 1,182 L), and it had a maximum range of 2,540 mi (4,088 km) with two drop tanks. The CA-15 weighed 7,540 lb (3,420 kg) empty, 10,764 lb (4,882 kg) with a normal load, and 12,340 lb (5,597 kg) at maximum overload. The Griffon 61-powered CA-15 had a maximum speed of 368 mph (592 km/h) at sea level, 448 mph (721 km/h) at 26,400 ft (8,047 m), and 432 mph (695 km/h) at 32,000 ft (9,754 m). The aircraft’s initial climb rate was 4,900 fpm (24.9 m/s), and it had a ceiling of 39,900 ft (12,162 m). The Griffon engine turned a 12 ft 6 in (3.81 m) diameter Rotol four-blade, wooden, constant-speed propeller. Initially, a 12 ft 1 in (3.68 m) propeller was used, the result of a damaged tip necessitating the blades being cut down. But a full-size propeller was fitted later during the flight test program.

CAC CA-15 side

This photo of the CA-15 illustrates the tailplane’s 10 degrees of dihedral and the relatively good view the pilot had over the nose of the aircraft.

Assigned serial number A62-1001, the CA-15 began taxi tests in February 1946. After a few modifications, the aircraft first flew on 4 March 1946 with Jim Schofield at the controls. The initial test flights went well, although the ailerons were noted as being heavy. Aileron control was improved, and numerous other refinements were made. Throughout the test flights, the CA-15 proved itself as an easy to fly aircraft with excellent performance and very good visibility.

After 16.5 hours of flying time, the CA-15 was handed over to the Royal Australian Air Force (RAAF) Aircraft Performance Unit (APU) No. 1 on 2 July 1946 for further flight testing. While at APU No. 1, the landing gear struts were over-pressurized, causing the CA-15 to bounce badly during taxi tests. The hopping action of the aircraft earned it the unofficial nickname “Kangaroo,” which has lasted over the years. Unfortunately, on 10 December 1946, a test gauge failed and resulted in the loss of all hydraulics. With no flaps and the unlocked gear partially extended, Flt. Lt. Lee Archer was forced to make an emergency landing that damaged the aircraft’s scoop and destroyed the wooden propeller. The failed gauge should have been removed before the aircraft was handed over to the RAAF. At the time, the CA-15 had 43.25 flying hours, and the damage was not too severe. However, with the war over and jets coming into service, there was no possibility of the CA-15 going into production. As a result, repairs to the one-off prototype were slow, after finally being approved in April 1947.

CAC CA-15 taxi

The CA-15 after a test flight. Note the scoop’s partially open cooling air exit flap. The aircraft in the background are most likely CAC-assembled CA-17s (P-51Ds), as the first CA-18 was not completed until 1947 (after the CA-15 was damaged).

CAC had repaired the CA-15’s airframe by October 1947, and the aircraft awaited a new propeller and radiator, which were the responsibility of the RAAF. The radiator was ready by February 1948, and the propeller followed in March. The CA-15 was returned to APU No. 1 on 19 May 1948. Later that month, the CA-15 grabbed headlines by achieving 502 mph (808 km/h) in a test flight over Melbourne, Victoria, Australia on 25 May 1948. This speed was recorded after Flt. Lt. Archer had leveled off at 5,000 ft (1,524 m) following a modest dive from 9,000 ft (2,743 m).

By February 1950, R-R wanted the two Griffon 61 engines back. In addition, there was no inventory of spare parts or any practical reason to continue flight testing of the CA-15. The engine was removed, and the CA-15 was scrapped, bringing an end to the highest performance aircraft ever designed and built in Australia.

CAC CA-15 rear

The CA-15 “Kangaroo” was a powerful fighter with performance rivaling that of the best piston-powered aircraft. Sadly, it was built too late for action in World War II and at a time when jet aircraft were the undeniable future.

Sources:
Wirraway, Boomerang & CA-15 in Australian Service by Stewart Wilson (1991)
Wirraway to Hornet by Brian L Hill (1998)
“Commonwealth CA-15: The ‘Kangaroo’ Fighter” by David Donald Wings of Fame Volume 4 (1996)
R-2800: Pratt & Whitney’s Dependable Masterpiece by Graham White (2001)

Hawker Fury Sabre LA610

Hawker Fury I (Sabre-Powered) Fighter

By William Pearce

While testing of the Tempest prototypes was still underway in 1942, the Hawker design team began to study ways to improve and lighten the fighter aircraft. Some of their ideas were influenced by the study of a German Focke-Wulf Fw 190 A-3 that had inadvertently landed in Britain in June 1942. The Fw 190 proved smaller and lighter that its Hawker-built contemporaries. In September 1942, the British Air Ministry issued Specification F.6/42 calling for a new fighter aircraft. Hawker proposed three versions of its improved Tempest, each to be powered by a different engine: the V-12 Rolls-Royce Griffon, the 18-cylinder Bristol Centaurus radial, and the H-24 Napier Sabre.

Hawker Fury Sabre LA610

The Napier Sabre-powered Hawker Fury LA610 in-flight exhibiting exactly what a high-performance aircraft should look like.

The Air Ministry supported Hawker’s designs under Specification F.2/43 issued in February 1943. In April 1943, Specification N.7/43 was issued for a new Navy fighter. Sydney Camm, Hawker’s chief designer, felt that arresting gear and folding wings could be added to the “improved Tempest” design to make it meet the requirements laid out in N.7/43. This plan was approved, and Specification N.22/43 was issued to Hawker for the new Navy fighter. Around this time, the two new Hawker aircraft received their official names: Fury (for the Royal Air Force’s land-based version) and Sea Fury (for the Fleet Air Arm’s naval version).

From the beginning, the preferred power plants were the Napier Sabre for the Fury and the Bristol Centaurs for the Sea Fury. Although the detailed design drawings for the Sabre-powered Fury were finished first, developmental delays of the new Sabre VII (NS.93/SM) engine resulted in the Centaurus- and Griffon-powered Furys being completed first. The Centaurus-powered Fury (NX798) first flew on 1 September 1944 followed by the Griffon-powered Fury (LA610) on 27 November 1944.

Hawker Fury Griffon LA610

The Hawker Fury LA610 originally flew with a Griffon engine and contra-rotating propellers. The large duct under the spinner housed the radiator, similar to that used on the Tempest V and VI.

Although the Air Ministry ordered 200 Sabre-powered Fury I aircraft in August 1944, there were rumors that Sabre production would be shut down following the war’s end. In October 1944, the Ministry of Aircraft Production (MAP) assured Hawker that Sabre production would continue. In November 1944, the MAP requested a Sabre-powered Fury prototype be built utilizing the Griffon-powered LA610 airframe. However, in February 1945 the Fury I order was reduced by 50 aircraft to 150. But in March 1945, two additional Sabre-powered prototypes (VP207 and VP213) were requested. Work to install a Sabre engine in LA610 began in July 1945. With the war over and the future of fighting aircraft pointing toward jet power, orders for the Fury I were reduced again in September 1945 to 120 units.

In December 1945, the Air Ministry had informed Hawker that ground attack would be the Fury I’s primary role. Hawker felt the aircraft was not suited for this because of its liquid-cooled engine, and it did not have the armor needed for a ground attacker. As a result, in February 1946, the number of Furys on order was further reduced to 60—and even those were in jeopardy. During this time, modifications of the LA610 airframe had been completed, but the Sabre VII engine was not ready. Rather than wait for the engine, a Sabre VA (2,600 hp / 1,939 kW) was substituted. Soon, a Sabre VII was installed, and Fury LA610 was flown for the first time with its intended power plant on 3 April 1946.

Hawker Tempest I HM599

The Hawker Tempest I (HM599), with its close-fitting cowl and wing radiators, was a stepping stone to the Fury I.

While the rest of the aircraft remained the same as the other prototypes, the power section of LA610 was completely different. A streamlined cowling was installed to cover the liquid-cooled Sabre engine. Coolant radiators were installed in the inboard wing sections, replacing additional fuel tanks. Cooling air would enter the wing’s leading edge, pass through the radiators, and exit via shutters under the wing. This configuration was similar to that used on the sole Tempest I prototype (HM599)—production did not occur because the Air Ministry perceived the wing radiators as too vulnerable to combat damage. The radiator shutters of the Fury I were automatically controlled based on engine temperature. A split duct under the spinner supplied intake air to the engine via the duct’s upper section. Air from the lower duct was directed through engine oil coolers and then out the bottom of the cowling.

Not only was it one of the most beautiful aircraft ever built, the Sabre-powered Fury proved to be the highest performance piston-engine aircraft built by Hawker. The 24-cylinder Napier Sabre engine was a horizontal H layout with two crankshafts. The engine had a 5.0 in (127 mm) bore, 4.75 in (121 mm) stroke, and displaced 2,238 cu in (36.7 L). The Sabre VII utilized water/methanol injection to boost power and was capable of 3,055 hp (2,278 kW). To transfer this power to thrust, the Fury I used a 13 ft 3 in (4.0 m) four-blade Rotol propeller. A five-blade propeller like the Sea Fury’s 12 ft 9 in (3.9 m) Rotol unit was considered, but the decreased weight of the four-blade unit proved decisive in its adoption.

Hawker Fury Sabre LA610 rear

This rear view of the LA610 Fury shows how well the 3,055 hp (2,278 kW) Sabre-engine was fitted to the airframe, enabling the aircraft to exceed 480 mph (775 km/h). Note the large 13 ft 3 in (4.0 m) four-blade propeller.

The Sabre-powered Fury had a top speed of 483 mph (777 km/h) at 18,500 ft (5,639 m) and 422 mph (679 km/h) at sea level. In contrast, the 2,560 hp (1,909 kw) Centaurus-powered Sea Fury had a top speed 460 mph (740 km/h) at 18,000 ft (5,487 m) and 380 mph (612 km/h) at sea level. The Sabre Fury’s initial rate of climb was 5,480 ft/min (27.8 m/s), and it could reach 20,000 ft (6,096 m) in 4.1 minutes. By comparison, The Sea Fury’s initial rate of climb was 4,320 ft/min (21.9 m/s), and it took 5.7 minutes to reach 20,000 ft (6,096 m). The Fury I’s service ceiling was 41,500 ft (12,649 m). All Fury and Sea Fury aircraft had the same 38 ft 5 in (11.7 m) wingspan. At 34 ft 8 in (10.6 m), the Sabre-powered Fury was 1 in (25.4 mm) longer than the Sea Fury. The Fury I had an empty weight of 9,350 lb (4,241 kg) and a loaded weight of 12,120 lb (5,498 kg).

On 14 August 1946, the remaining Fury I aircraft on order were cancelled. Of the three Fury I prototypes, LA610 would remain with Hawker for testing, VP207 would be completed and loaned to Napier for engine testing, and VP213 would be used for parts and not completed. VP207 was chosen to go to Napier because it had a larger radiator that could handle developmental power increases of the Sabre VII engine. With the cancellation of the Fury I there was no longer a need for the Sabre VII engine, and its development was stopped; Napier would not take over VP207. VP207 was completed by Hawker and first flew on 9 May 1947. Hawker retained the aircraft as a company demonstrator for a short period of time. The final disposition of LA610 and VP207 has not been definitively found, but it is believed both aircraft were scrapped in the late 1940s.

Hawker Fury Sabre LA610 taxi

Fury LA610 preparing for a flight. The air scoop under the spinner, and the wing radiators can clearly be seen in this image.

Although the Fury never progressed beyond the prototype phase, the Sea Fury did enter production, with some 789 aircraft built (number varies by source)—including prototypes and 61 two-seat T.20 trainers. Sea Furys served in Korea, were the last front-line piston-engine aircraft operated by the Royal Navy Fleet Air Arm, and were sold to and used by various other countries. A number still fly today, but due to the rarity of the Bristol Centaurus engine, many have been re-engined with Wright R-3350s. In addition, two Sea Furys have been built up for racing with Pratt & Whitney R-4360 engines, and one has a Pratt & Whitney R-2800. But none have looked quite as stunning or performed as well (in military trim) as the Napier Sabre-powered Hawker Fury I.

Hawker Fury Sabre VP207

The Sabre-powered Hawker Fury VP207 at the Society of British Aircraft Constructors show at Radlett in September 1947. Many believe the aircraft was painted silver with a blue stripe, while others believe the stripe was red. (Robert Archer image via Victor Archer / American Motorsports Coverage)

Sources:
Sea Fury in British, Australian, Canadian & Dutch Service by Tony Buttler (2008)
British Secret Projects Fighters & Bombers 1935-1950 by Tony Buttler (2004)
Jane’s All the World’s Aircraft 1947 by Leonard Bridgman (1947)
Hawker Sea Fury (Warbird Tech Volume 37) by Kev Darling (2002)
RAF Fighters Part 2 by William Green and Gordon Swanborough (1979)
War Planes of the Second World War: Fighters Volume Two by William Green (1961)
Tempest: Hawker’s Outstanding Piston-Engined Fighter by Tony Buttler (2011)
Hawker Typhoon, Tempest and Sea Fury by Kev Darling (2003)
Aircraft Engines of the World 1947 by Paul H. Wilkinson (1947)

Northrop YC-125 JATO

Northrop N-23 Pioneer and N-32 / YC-125 Raider

By William Pearce

As World War II wound down, Northrop looked for opportunities to expand its aviation products. At the time, various reports forecasted a need for a rugged, low-cost, transport aircraft to serve under-developed airfields for emerging commercial routes following World War II. To meet that need, Northrop designed and built the N-23 Pioneer transport at its own expense. The Pioneer was unlike any aircraft that Northrop had built.

Northrop N-23 Pioneer

The Northrop N-23 Pioneer seen shortly after its rollout at Hawthorne, California and before its registration (NX8500H) was applied. Note the single window along the fuselage.

The N-23 Pioneer was a trimotor, high-wing aircraft of all-metal construction. Its robust fixed landing gear, with long struts, enabled the aircraft’s use on unimproved runways. To allow for short-field operation, large flaps made up 80% of the wing’s trailing edge. In addition, another wheel could be added to the inboard side of each main gear strut to reduce the aircraft’s load footprint for soft field operation. Outboard of the large flaps were small ailerons that acted with wing spoilers to control the aircraft’s roll. This configuration was similar to that used on the Northrop P-61 Black Widow.

The Pioneer was engineered with remote field operations in mind. Common parts were used when possible; all three engine installations were identical, as were the vertical and horizontal stabilizers. The Pioneer was designed with large panels to allow easy access to critical parts for maintenance and repair.

Northrop N-23 take off

The Northrop Pioneer performing a short field takeoff from the Conejo Valley Airport in Southern California. The Pioneer’s short field performance enabled it to operate out of airfields normally limited to small aircraft. Note that the fuselage has been modified with passenger windows.

The Pioneer could be fitted with 36 seats for passenger service or carry up to 10,000 lb (4,536 kg) of cargo. Quick-change fittings were featured in the floor of the Pioneer’s cabin; they enabled easy reconfiguration of the aircraft’s interior from passenger transport to cargo transport. Long objects (such as pipe or timber) up to 36 ft (11 m) could be loaded through a hatch under the aircraft’s nose.

The Pioneer was powered by three 800 hp (597 kW) Wright R-1300 engines. Each engine turned a fixed-pitch, two-blade Hamilton Standard propeller. The aircraft had an 85 ft (25.9 m) wingspan and was 60 ft 7 in (18.4 m) long. It had a maximum speed of 193 mph (311 km/h), a cruising speed of 150 mph (241 km/h), and a range of 1,750 mi (2,816 km).

Northrop YC-125 Raider

YC-125 Raiders on the Northrop production line. Note the various engine access panels. The wings’ leading edge panels allowed access to fuel lines, control cables, and wiring.

First flown on 21 December 1946 by Max Stanley, the Pioneer proved to be a very capable aircraft. It could take off in fewer than 400 ft (122 m). At a gross weight of 25,500 lb (11,567 kg), the Pioneer could take off in 700 ft (213 m) and land in 600 ft (183 m). The aircraft was operated out of various unimproved and short fields in Southern California. Unfortunately, with the influx of cheap, surplus World War II transports available in the post-war marketplace, there was little interest in the rugged Pioneer.

After a year of test flights, the Pioneer was used to test an experimental dorsal fin. During a flight on 19 February 1948, the fin broke loose and damaged the Pioneer’s tail surfaces, making the aircraft uncontrollable. Test pilot Latham A. “Slim” Perrett did what he could to steady the aircraft to allow the copilot and an engineer to parachute to safety. Sadly, there was no time for Perrett to escape.

Northrop YC-125 air

A Northrop YC-125B on a flight by the coast. Note the redesigned empennage compared to the Pioneer.

Despite the crash, the Air Force was interested in the Pioneer’s capabilities. In March 1948, Northrop was issued a contract for 13 aircraft developed from the Pioneer. The new aircraft was the N-32 Raider and was designated YC-125 by the Air Force. The first version was the YC-125A, an assault transport. An order for 10 additional YC-125B aircraft followed. The YC-125B was intended for Arctic rescue. The two versions of the YC-125 differed only in internal equipment.

Northrop YC-125 JATO

A Northrop YC-125 Raider uses six JATO bottles to take off fully loaded in under 500 ft (152 m).

The YC-125 Raider was very similar to the Pioneer, but it had a redesigned rear fuselage that incorporated a 9 ft (2.7 m) by 6 ft 6 in (2.0 m) ramp for loading and unloading equipment. The addition of the loading ramp led to a redesign of the aircraft’s empennage. The YC-125’s tailwheel strut could be extended to allow for better loading ramp access. Six JATO (jet-assisted take off) bottles could be used to enable a fully loaded 40,900 lb (15,552 kg) YC-125 to take off in 500 ft (152 m).

The YC-125 was powered by three 1,200 hp (895 kW) Wright R-1820 engines. Each engine turned a constant speed, three-blade Curtiss Electric propeller. The propellers’ pitch could be reversed to shorten the landing distance to as little as 330 ft (100 m). The aircraft had an 86 ft 6 in (26.4 m) wingspan and was 67 ft 1 in (20.4 m) long. The YC-125 had a maximum speed of 207 mph (333 km/h) and a cruising speed of 171 mph (275 km/h). The aircraft’s maximum range was 1,850 mi (2,977 km), and it could carry 32 troops or 12,000 lb (5,443 kg) of cargo.

The YC-125 made its first flight on 1 August 1949 with Stanley at the controls. Initial flight tests went well, and all 23 aircraft were delivered to the Air Force by the end of 1950. However, the YC-125 was found to be underpowered during service trials. As a result, the aircraft was thought to have little use in its intended roles. The Air Force had other, more versatile aircraft and helicopters that could be used in place of the YC-125s. Soon, all YC-125s were stationed at Sheppard Air Force Base in Texas and used for ground instructional training. In 1955, they were declared surplus, and around 19 YC-125s were sold to Frank Ambrose Aviation in Florida. That company then resold many of the YC-125s to various entities in South America, where they were used as rough field transports. Some served into the 1970s, doing the type of work for which the N-23 Pioneer was originally designed.

Northrop YC-125A Pima

The Northrop YC-125A of the Pima Air & Space Museum. This aircraft was donated by Robert A. Gallaher. (Pima Air & Space Museum image)

There are two known surviving YC-125s. Both were recovered after their service in South America. The Pima Air & Space Museum in Tuscon, Arizona has a YC-125A still in the livery it wore while serving for Triplay y Maderas de Durango, S.A., a lumber company in Durango, Mexico. The National Museum of the United States Air Force (NMUSAF) in Dayton, Ohio has a YC-125B. This aircraft was recovered from Zacateas, Mexico by Asher Ward and Darryl Greenamyer in the early 1990s.

Ward and Greenamyer had previously recovered a YC-125A for the NMUSAF, but the aircraft crashed in Tulsa, Oklahoma on 29 June 1988. As a result of a corroded wire, the propeller of the left engine went into reverse pitch shortly after takeoff. Ward and Greenamyer escaped with minor injuries. This was the last flight of the last airworthy YC-125.

Northrop YC-125B NMUSAF

The Northrop YC-125B of the National Museum of the United States Air Force. Note the additional main wheel added to the inboard side of each main gear strut. (NMUSAF image)

Sources:
Northrop: An Aeronautical History by Fred Anderson (1976)
American Military Transport Aircraft Since 1925 by E. R. Johnson (2013)
http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=784
http://www.warbirdinformationexchange.org/phpBB3/viewtopic.php?p=167612
http://newsok.com/rare-airplane-loses-power-crashes-at-airport-in-tulsa/article/2230816
http://www.ntsb.gov/aviationquery/brief.aspx?ev_id=20001213X25943&key=1

Myasishchev M-50 bottom

Myasishchev M-50 / M-52 Bounder

By William Pearce

In the midst of the cold war, the United States and the Soviet Union constantly sought to outdo one another or at least match each other. As the United States was developing the Convair B-58 Hustler bomber capable of Mach 2 speeds, the Soviet Union endeavored to design and build its own Mach 2 bomber. In 1955, the V. M. Myasishchev Experimental Design Bureau, or OKB-23 (Opytno-Konstruktorskoye Byuro-23), was tasked to develop the new Mach 2 strategic bomber. Under chief designer Georgi Nazarov and with the assistance of the TsAGI (Tsentral’nyy Aerogidrodinamicheskiy Institut, the Central Aerohydrodynamic Institute), a number of designs were evaluated and tested in a wind tunnel. Ultimately, a design was chosen that could meet the desired performance goals and was technically feasible to build. This aircraft became the Myasishchev M-50.

Myasishchev M-50 flyby

The Myasishchev M-50 with a MiG-21 escort, giving some perspective to the size of the M-50.

In general, the M-50 resembled an enlarged Mikoyan-Gurevich MiG-21. The M-50 was comprised of a long, slender fuselage with a large delta wing mounted in the middle. The fuselage had a circular cross-section with a bulge that ran down its spine for control and fuel lines. All fuel was housed in the fuselage and could be transferred between the extreme fore and aft tanks to counteract trim changes as the M-50 accelerated to or decelerated from supersonic flight.

The pilot and co-pilot sat in tandem at the very front of the aircraft. The M-50 was designed to operate at very high altitudes, and the crew was required to wear pressure suits in case of cabin depressurization or ejection. The aircraft was fitted with downward-ejecting seats. This configuration also facilitated crew entry and exit; the hatch under each seat opened and the seat lowered for access.

Myasishchev M-50 ground hatch

The M-50 with the hatches under the crew positions open. Also note the open bomb bay. The sole M-50 was painted with various radio call numbers.

The M-50’s wings were very thin and could not house any fuel. Under each wing was a pylon-mounted engine about 2/3 of the way toward the wingtip. On the top of the wing and above the engine pylon was a wing fence. Each wing had a second engine mounted at its tip. The wing was swept back 50 degrees from its root to the inboard engine and 41.5 degrees to the second engine at its tip (some sources say the sweep was 57.57 and 54.42 degrees respectively). The wing featured large, rectangular, double-slotted flaps and tapered outboard ailerons. Reportedly, when the flaps were deployed, the ailerons dropped down to further reduce the M-50’s landing speed. All three tail surfaces, including the vertical stabilizer, were all-moving. Each tail surfaces had an anti-flutter weight barb extending from its tip. All flight control surfaces were hydraulically operated.

The M-50’s landing gear was of bicycle configuration, with a four-wheel bogie located both fore and aft of the bomb bay. Additional forward retracting outrigger gear was mounted just inboard of each wingtip engine. In order to accommodate a weapons bay large enough to carry the 36 ft 1 in (11 m) long M-61 cruise missile, the rear main gear was placed near the tail, well behind the aircraft’s center of gravity. This gear placement drastically increased the speed needed for rotation at takeoff, perhaps even making takeoff impossible. To alleviate this issue, the M-50’s nose gear was equipped with a double-extension hydraulic strut. At 186 mph (300 km/h) the strut would automatically extend, rotating the aircraft 10 degrees nose-up. The gear also had an emergency steel skid that could be hydraulically lowered to the runway upon landing, acting as a drag anchor, in case there was an issue with the standard three-parachute braking system.

Myasishchev M-50 rear

A rear view of the Myasishchev M-50 showing its all-movable tail surfaces. Also note the hump that housed fuel and control lines running along the aircraft’s spine.

The M-50 was 188 ft 7 in (57.48 m) long, had an 82 ft 4 in (25.1 m) wingspan, and was 27 ft 1 in (8.25 m) tall. The aircraft’s empty weight was 173,855 lb (78,860 kg), and its maximum weight was 319,670 lb (145,000 kg). The M-50’s forecasted performance included a service ceiling of 45,930 ft (14,000 m), a range of 8,075 mi (13,000 km), a bomb load of 11,000 lb (5,000 kg), and a top speed of 1,210 mph (1,950 km/h), or Mach 1.84.

Construction of the M-50 began in April 1956. Originally, the M-50 was to be powered by four Zubets RD-16-17 afterburning turbojets with 40,765 lb (181.32 kN) of thrust. However, the aircraft’s construction outpaced the engine’s development. When the M-50 was rolled out in July 1958, four non-afterburning Dobrynin VD-7BA turbojets of 21,495 1b (95.61 kN) thrust had been temporarily installed. The aircraft was re-designated M-50A as a result of the engine change.

In October 1958, the M-50A was disassembled and moved to the Zhukovskiy flight test center. Here it underwent taxi tests that indicated further modifications were needed. After the modifications, M-50A finally took to the air on 27 October 1959 with Nikolay I Goryainov and A S Lipko at the controls. Initial flight testing progressed rapidly; however, the M-50A was damaged in a ground accident on 12 May 1960. During an engine run-up, the aircraft jumped its wheel chocks and collided with the parked Myasishchev 3ME bomber prototype. The 3ME was scrapped as a result of the damage, but the M-50A was repaired and flying again in two months.

Myasishchev M-50 bottom

The Myasishchev M-50 makes a pass at the Tushino Air Show on 9 July 1961. Note the similar layout of the M-50 and its MiG-21 escorts.

In April 1961, the two inner VD-7BA turbojets were swapped with afterburning VD-7AM engines of 35,275 lb (156.91 kN) thrust. Slightly derated VD-7BA engines of 20,945 lb (93.16 kN) thrust were installed on new wingtip mounts. These mounts were wingtip extensions that housed new rearward retracting outrigger gear and increased the wingspan by 32 ft 10 in (10 m) to 115 ft 2 in (35.1 m). All engine installations were redesigned to incorporate ram inlets above the nacelle for additional cooling airflow.

Flight tests continued. With the underpowered engines installed, the M-50A was unable to achieve supersonic flight. Even in a shallow dive from altitude, the aircraft’s speed would not go above Mach 0.99, or 650 mph (1,050 km/h). In addition, the M-50A’s range fell 2,110 mi (3,400 km) short of expectations to 5,965 mi (9,600 km). During flight tests, the sole M-50A was painted with a various radio call numbers—023, 022, 12, and 05—to confuse any western observers.

Myasishchev M-52 mock-up

The Myasishchev M-52 mockup. Note the side-by-side cockpit configuration and the missile positioned near its mount under the wing. The small horizontal stabilizer is barely visible on top of the tail.

On 9 July 1961, the M-50A was escorted by two MiG-21 fighters as it made a flyby pass at the Tushino Air Show near Moscow. Western observers were impressed by the large, exotic, and loud aircraft. This appearance resulted in NATO assigning the codename “Bounder” to the M-50. However, what the observers did not know was that this was the M-50A’s last flight. It had only flown 19 times.

The M-52, a further development of the M-50, had been under construction since November 1958. The M-52 retained the four Zubets RD-16-17 engines (some say RD-17-18 engines rated at 39,020 lb / 173.58 kN). The wingtip engines were mounted on larger extensions. The M-52 had side-by-side seating for the pilot and co-pilot, and a third crew member was stationed in its nose. A small, delta-shaped horizontal surface was added to the top of the vertical stabilizer. Planned weapon upgrades for the M-52 included twin tail guns and provisions to attach a cruise missile on each side of its fuselage, under the wings.

Myasischev_M-50_@_Central_Air_Force_Museum OMP

The Myasischev M-50 on display in the Central Air Force Museum at Monino Airfield. (Maarten image via Wikimedia Commons)

Soviet Premier Nikita Krushchev felt future offensive and defensive weapons would be based on intercontinental ballistic missiles (ICBMs) rather than strategic bombers. As a result, the Myasishchev M-50 and M-52 projects were cancelled. OKB-23 was closed, and its personnel were redirected to another organization for ICBM work.

The M-50A and the nearly finished M-52 eventually ended up parked at Ramenskoye Airport in Zhukovsky (near Moscow), Russia. In 1968, the M-50A was relocated to the Central Air Force Museum at Monino Airfield (also near Moscow) where it is currently on display. The M-52 was scrapped in the 1970s.

Below is a video of the Myasishchev M-50 uploaded to YouTube.

Sources:
Soviet X-Planes by Yefim Gordon and Bill Gunston (2000)
Aircraft of the Soviet Union by Bill Gunston (1983)
http://www.airvectors.net/avbison.html
http://www.testpilot.ru/russia/myasishchev/m/50/m50_e.htm
http://www.testpilot.ru/russia/myasishchev/m/52/m52.htm
Unflown Wings by Yefim Gordon and Sergey Komissarov (2013) *No real info on the M-50 or M-52 but does contain a number of other projects that are often attributed to these aircraft.

Sud-Ouest SO8000 front

Sud-Ouest (SNCASO) SO.8000 Narval

By William Pearce

In the immediate aftermath of World War II, France worked to rebuild its military. Much progress had been made in aviation during the war years, and this was now an area of special focus. The French Navy (Marine Nationale) expressed an interest in a new aircraft that could serve in fighter, interceptor, and ground attack roles. Although other navies were beginning the transition to jet aircraft, the French Navy requested this new aircraft to be piston-powered.

Sud-Ouest SO8000 side

Side view of what is believed to be the first Sud-Ouest SO.8000 Narval, which was actually the second aircraft to fly. This image illustrates the good visibility provided to the pilot by the cockpit’s configuration. Note the radio antenna mast under the cockpit that was unique to the first aircraft.The aircraft is also lacking gear doors.

On 31 May 1946, the Société nationale des constructions aéronautiques du sud-ouest (often abbreviated as SNCASO or shortened to Sud-Ouest) was selected to design this new aircraft and build two prototypes. Arsenal de l’Aéronautique (Arsenal) was selected to develop its power plant. The original plan was to build five prototype aircraft followed by 65 production aircraft. Sud-Ouest moved quickly and designed an unusual single-engine pusher aircraft with twin booms supporting its tail. The aircraft was designated SO.8000 and given the name Narval (Narwhal).

Designed by Jean Dupuy, the SO.8000 was an all-metal aircraft. The inboard leading edge of its wing was sweptback 24 degrees, while the outboard section was sweptback 13.5 degrees and incorporated a dihedral angle. The aircraft had large double slotted flaps to decrease its landing speed for carrier operations. Roll control was achieved by a combination of small ailerons at the wingtips and spoilers. The twin booms extended from the inner wing sections and each supported a fin extending above and below the boom. The horizontal stabilizer spanned between the two tails and was attached near their top. On the second aircraft, which was the first to fly, the elevator was extended beyond the vertical tail fins and incorporated a horn balance.

Sud-Ouest SO8000 front

The first SO.8000 had its pitot tube located on an outrigger by the cockpit and not in the wing leading edge like the second aircraft. This view shows the Narval’s air inlets for its radiator and the air intake for its engine.

The pilot was enclosed in a sliding bubble-style canopy near the front of the aircraft. This configuration provided the pilot with an excellent view. Behind the cockpit and on each side of the aircraft were cooling air intakes for the radiator. After flowing through the radiator, the cooling air exited around the spinner of the eight-blade contra-rotating propellers. The air intake for the Arsenal 12H engine was located on the upper left side of the rear fuselage.

Lacking the time to design and test a completely new engine, Arsenal turned to the German Junkers Jumo 213A as a starting point. Arsenal reworked the Jumo 213 and created the 2,100 hp (1,566 kW) 12H. The 12H was an inverted V-12 with a 5.9 in (150 mm) bore, a 6.5 in (165 mm) stroke, and a displacement of 2,135 cu in (35.0 L). However, more power was desired, and Arsenal increased the 12H’s output to 2,250 hp (1,678 kW). This power increase caused some engine reliability problems. In 1948, the aircraft engine branch of Arsenal was absorbed by the Société nationale d’études et de construction de moteurs d’aviation (SNECMA), and the engine became the SNECMA Arsenal 12H.

Sud-Ouest SO8000 Narval

Another view of the first Narval illustrating its wing sweep and contra-rotating propellers.

The SO.8000 Narval was to be equipped with six 20 mm cannons in its nose. Additionally, underwing hard points would accommodate 2,205 lb (1,000 kg) of bombs. However, it is unlikely that the prototypes were ever armed. The SO.8000 had a 38 ft 7 in (11.75 m) wingspan and was 38 ft 9 in (11.80 m) long. On its tricycle landing gear, the aircraft stood 10 ft 6 in (3.20 m) tall. The Narval had an empty weight of 10,626 lb (4,820 kg) and a loaded weight of 15,432 lb (7,000 kg). The predicted performance of the SO.8000 was a maximum speed of 453 mph (730 km/h) at 24,606 ft (7,500 m) and a landing speed of 96 mph (155 km/h). The aircraft had an estimated 2,796 mi (4,500 km) range at 329 mph (530 km/h).

Sud-Ouest SO8000 rear

This image provides a good view of the first SO.8000’s elevator. Note how the horizontal stabilizer does not extend beyond the tail fins.

Most sources indicate that the second prototype (registered as F-WFKV) was completed and flew first, taking to the air on 1 April 1949 with Jaques Guignard at the controls. The first prototype’s first flight was on 30 December 1949 with Roger Carpentier (some sources say Jaques Guignard) as the pilot. The SO.8000 experienced numerous problems during its flight test program. The aircraft handled poorly and possessed some undesirable control characteristics, such as instability at low speed. Efforts were made to improve control and performance, including replacing the Chauvière contra-rotating propellers with a Rotol unit, but the results were still not satisfactory. In addition, the 12H engine proved to be unreliable. The flight tests revealed that the aircraft would not achieve its expected performance, and flight evaluations of the SO.8000 at the Centre d’Essais en Vol (Flight Test Center) in January 1950 were mostly unfavorable.

Given the trouble with the aircraft and the dominating performance of jet aircraft, further development of the SO.8000 was halted. A contributing factor in the Narval’s cancellation was the allocation of US Grumman F6F Hellcats and Vought F4U Corsairs to France. The second prototype took its 43rd and final flight on 8 January 1950. The first prototype was only flown twice. Proposals were submitted to convert the aircraft to jet-power as the SO.8010, but no further action was taken. Apparently, both SO.8000 aircraft were scrapped after the program was terminated.

Sud-Ouest SO8000 ground

In contrast to the image above, the elevator of the second SO.8000, which was actually the first to fly, can be seen extending past the tail fin in this view. The radio mast for the second aircraft was located on the back of the aircraft behind the cockpit, and note the pitot tube is on the far wing. In this image, the nose gear door has been attached but the main gear doors have not.

Sources:
The Complete Book of Fighters by William Green and Gordon Swanborough (1994)
French Secret Projects 1: Post War Fighters by Jean-Christophe Carbonel (2016)
Jane’s All the World’s Aircraft 1949-1950 by Leonard Bridgman (1949)
Aircraft Engines of the World 1951 by Paul H. Wilkinson (1951)
http://www.avionslegendaires.net/avion-militaire/sud-ouest-so-8000-narval/

The sleek Argentine FMA IAe30 Namcu with what appears to be a damaged aileron.

FMA IAe 30 Ñancú

By William Pearce

Following World War II, Argentina experienced an influx of former German and Italian engineers. One such engineer was Cesare Pallavicino, formally with the Italian aircraft firm Caproni. Pallavicino was brought into the Instituto Aerotécnico (IAe) to design a twin-engine escort fighter. This project would become the IAe 30 Ñancú.

The sleek Argentine FMA IAe30 Namcu with what appears to be a damaged aileron.

The sleek Argentine FMA IAe 30 Ñancú with what appears to be a damaged aileron.

Initially, Pallavicino submitted two jet-powered designs and one piston-powered design. The piston-powered design was chosen for development as the IAe 30. In addition to Argentine engineers, Pallavicino was also able to bring on a number of former Caproni engineers to work on the project. Three IAe 30s were ordered and construction of the first prototype began in July 1947.

Powered by two 1649 cu in (27.0 L) Rolls-Royce Merlin 134/135 engines that produced 2,035 hp (1,517 kW) each, the Ñancú resembled the de Havilland Hornet, but it was an original, all-metal design. The propellers were four-blade de Havilland units, 12 ft (3.66 m) in diameter. The aircraft had a wingspan of 49 ft 3 in (15 m) and a length of 37 ft 10 in (11.52 m). The aircraft’s empty weight was 12,313 lb (5,585 kg), and it had a gross weight of 19,301 lb (8,755 kg). The IAe 30’s top speed was 460 mph (740 km/h) and cruise speed was 311 mph (500 km/h). Range was 1,678 mi (2,700 km).

The IAe 30 during a ground run of its Merlin engines.

The IAe 30 during a ground run of its Merlin engines. Note the streamlined engine nacelles.

The proposed armament consisted of four 20 mm Hispano-Suiza cannons mounted in the aircraft’s lower fuselage, under the wings. In addition, a 550 lb (250 kg) bomb could be carried under the fuselage, and five 3.25 in (83 mm) rockets could be fitted under each wing. However, the prototype was never armed.

The IAe 30 team was under a lot of pressure to quickly complete the aircraft. A few corners were cut during design and testing but the aircraft, mostly complete, was ready for ground tests on 8 June 1948 (some say 9 June). Despite wind tunnel tests not being completed, the IAe 30 took to the air for the first time with Captain Edmundo Osvaldo Weiss at the controls on 18 July 1948 (some say 17 July). Initial flight tests revealed that the aircraft performed well and possessed good handling characteristics.

On a cross country flight from Córdoba to Buenos Aires on 8 August 1948, the Ñancú averaged 404 mph (650 km/h) at only 60% power. While flying level at 18,370 ft (5,600 m) during the flight, the aircraft reached 485 mph (780 km/h) with the aid of a strong tail wind. Based on the initial performance of the aircraft, an order for 210 IAe 30s was placed.

The Ñancú in flight displaying is resemblance to a de Havilland Hornet.

The Ñancú in flight, displaying is resemblance to the de Havilland Hornet.

During  continued testing the aircraft achieved 560 mph (900 km/h) in a dive. Only minor changes of the aircraft were required, but it took a long time for the changes to be implemented. Part of the delay was poor communication between the test pilots and the design staff. One pilot who flew the Ñancú and reported very favorable results was Professor Matthies, better known as Kurt Tank. Tank was a German aircraft designer who had worked for Focke-Wulf during World War II, designing the Fw 190 fighter, among others. After the war, he immigrated to Argentina and assumed the pseudonym Pedro Matthies.

In early 1949, the prototype was badly damaged when test pilot Carlos Fermín Bergaglio misjudged a landing. Although the aircraft could have been repaired, there was no interest in doing so. The prototype had achieved its design goals and showed great potential. However, the jet age had arrived, and the Fuerza Aérea Argentina (Argentine Air Force) was focused on jet aircraft for their future fighters. Argentina had purchased 100 Gloster Meteor jet fighters, which were delivered by September 1948. Citing “financial reasons,” the order for the IAe was cancelled in late April 1949. The Fabrica Militar de Aviones (FMA), the state-run overseer of the IAe, made the decision to abandon the project. The damaged prototype and the two unfinished prototypes were scrapped, ending the story of one of the last piston-engine fighters to be developed.

A rare color image of the IAe 30.

A rare color image of the IAe 30. Note the split rudder.

Sources:
“IAe Ñancú: Argentinian Eaglet,” Wing of Fame Volume 5 by Jim Winchester (1996)
The Complete Book of Fighters by Green and Swanborough (1994)
Jane’s All the World’s Aircraft 1949-1951 by Leonard Bridgham (1949)
http://en.wikipedia.org/wiki/IAe_30_%C3%91anc%C3%BA