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Seversky P-35
P-35 (36-0404) marked as P-35A at the National Museum of the USAF
Type	Fighter
Manufacturer	Seversky
Designed by	Alexander Kartveli
Maiden flight	15 August 1935
Introduced	1937
Retired	September 1952 (Sweden)
Primary users	United States Army Air Force Swedish Air Force
Number built	136
Unit cost	US$22,500 [1]
Variants	P-43 Lancer

The Seversky P-35 was a fighter aircraft built in the United States in the late 1930s. The P-35 was the first single-seat fighter in U.S. Army Air Corps to feature all-metal construction, a retractable landing gear and an enclosed cockpit.

Contents 1 Design and development 2 Operational history 2.1 Swedish service 3 Variants 4 Operators 5 Survivors 6 Specifications (P-35A) 7 References 8 External links 9 Related content

The origins of the P-35 trace back to the Seversky SEV-3 amphibious aircraft which was developed into the Seversky BT-8 basic trainer. The trainer proved grossly underpowered and was quickly replaced by the North American BT-9. Seversky's chief designer Alexander Kartveli also proposed a two-seat fighter derivation of the SEV-3 called SEV-2XP. The aircraft, powered by a 735 hp (550 kW) Wright R-1670 radial engine, had fixed landing gear in aerodynamic spats and was armed with one 0.50 in and one 0.30 in forward-firing machine guns plus an additional 0.30 in for rear defence.

When USAAC announced a competition for a new single-seat fighter in 1935, Seversky sent SEV-2XP confident that it would win in spite of being a two-seater. However, the aircraft was damaged during its transit to the fly-offs at Wright Field. Fortunately for the company, USAAC delayed the fly-offs until March 1936 which allowed Seversky time to rework the fighter into the single-seat SEV-1XP with retractable landing gear. As the aircraft was underpowered, the powerplant was upgraded to a Pratt & Whitney R-1830-9 Twin Wasp with 850 hp (634 kW) available on takeoff. The SEV-1XP won the USAAC competition on 16 June 1936, beating Curtiss Model 75 Hawk in the finals, with the company awarded an order for 77 P-35 fighters.

Ironically, because of the unrest in Europe, the USAAC also ordered 210 Curtiss P-36s. The difference in the number in the orders was in part due to the P-35 being considerably more expensive (more than $1,500 per aircraft) and, in part, due to the sale of 2PA two-seat aircraft to the Japanese Navy (see below). Modifications from SEV-1XP to production P-35 included partial instead of complete mainwheel fairings, seven degrees of dihedral to the outer wing panels and revised canopy.

The first production aircraft were transferred to the USAAC in 1937. Only 76 P-35s were built with the last production aircraft finished as Seversky XP-41.

Aiming to increase sales, Alexander P. de Seversky personally took a P-35 on a tour around Europe in early 1939; in the process, he became the first American pilot to fly the Supermarine Spitfire. After he was voted out by the Board of Directors, Republic (as the company became known after reorganization), sold Sweden the EP-106 (Export Pursuit), a refinement of the P-35 designated to replace the country's aging Gloster Gladiator biplanes. The EP-106 was powered by a Pratt & Whitney R-1830-45 Twin Wasp engine with 1,000 horsepower (750 kW), improving its performance by over 25 mph (40 km/h). The Swedes ordered a total of 120 EP-106s, with initial order placed in mid-1939, and 60 aircraft delivered. The aircraft were armed with two 7.9 mm machine guns in the nose and one 13.2 mm machine gun in each wing, and could carry 350 lb (160 kg) of bombs. The aircraft were given the Swedish Air Force designation J 9.

Seversky also built a two-seat version of the P-35 designated 2PA. Two aircraft, one with conventional landing gear and one with floats, along with the manufacturing license were sold to the USSR but it appears that the Soviets never put it into production. In what proved to be an unpopular move for Seversky, 20 2PA-B3s were sold to the Japanese Navy which briefly employed them in the Second Sino-Japanese War as Navy Type S Two-Seat Fighter or A8V-1 (Allied codename "Dick"). The Japanese were unimpressed with the aircraft and eventually relegated two of them to the Asahi Shimbun newspaper as "hacks." Sweden ordered 52 2PAs (Swedish designation B 6) but received only two prior to the U.S. embargo directed to combatants. The remaining 50 aircraft were appropriated by the USAAC, re-armed with 0.30 in and 0.50 in machine guns, and used as advanced trainers named AT-12 Guardsman.

The P-35's successor, the P-43 Lancer was based on the P-35 (and its lightweight higher-speed counterpart, the P-44 Rocket) and was already outdated when compared to British and German warplanes currently in service over Europe. Alexander Kartveli began to consider its successor using lessons learned from the P-35, P-43 and P-44, eventually emerging as the P-47 Thunderbolt.

The first P-35s were delivered to the 1st Pursuit Group stationed at the Selfridge Field in Michigan. The aircraft utilized a wet wing to save weight and ground personnel quickly learned about the persistent fuel leaks. The P-35's performance was poor even by contemporary standards and, although USAAC fliers appreciated the aircraft's ruggedness, it was already obsolescent by the time deliveries were finished in 1938. Nonetheless, the P-35 design served as the basis for the promising Italian Reggiane Re.2000 Falco fighter.

On 18 June 1940, United States declared an embargo against exporting weapons to any nation other than Great Britain. Optimistically, Republic continued to manufacture EP-106s which, by the 24 October 1940 order, 60 were taken over by the USAAC as the P-35A. The aircraft were re-armed to American standards with 0.30 in and 0.50 in machine guns but apparently retained metric flight instruments and flight manuals written in Swedish. Of these, three aircraft were kept in United States as instructional airframes for mechanics, and 57 were sent to the Philippines. About ten of these were quickly lost in accidents; the rest fought in the futile defense of the islands in December 1941 and January 1942 but were hopelessly outclassed by the Japanese fighters. Lack of armor and self-sealing fuel tanks made the aircraft extremely vulnerable and by 12 December 1941, only eight P-35As were still in flying condition. In 1942, surviving P-35As were redesignated RP-35A, the letter "R" indicating the aircraft were "restricted" or unfit for combat. Their last sortie was flown over Macajalar Bay on 3 May.

The Swedish Air Force received 60 J 9s in the spring-summer 1940. The aircraft were amongst other units assigned to the F8 air wing protecting Stockholm, replacing its outdated Gloster Gladiators.^[2] Swedish J 9s served with Flygvapnet as a fighter until 1946. Later, ten aircraft were equipped with cameras but retained their J 9 fighter designation and, in addition, a number of others were used for liaison and general flight training. The last seven J 9 aircraft remained in service until September 1952.^{[citation needed]}

SEV-1XP

Single-seat fighter prototype

SEV-2XP

Two-seat fighter prototype

SEV-7

Single-seat fighter prototype, fitted with a Pratt & Whitney R-1830-9 Twin Wasp radial piston engine. The aircraft was later redesignated AP-1.

EP-106

Single-seat fighter version for Sweden.

P-35

First production version, Pratt & Whitney R-1830-9 engine with 850 hp (634 kW).

EP-1

Export version of the P-35.

P-35A

Appropriated EP-106 destined for Sweden, Pratt & Whitney R-1830-45 radial piston engine with 1,050 hp (783 kW) and increased armament.

J 9

Swedish designation of the P-35A.

RP-35A

Surviving P-35A designated as unfit for combat duties.

2PA

Two-seat version with rear gunner.

A8V-1 "Dick"

Two-seat 2PA used by the Japanese Navy.

B 6

Swedish designation of the 2PA.

AT-12 Guardsman

Two-seat advanced trainer, appropriated 2PA destined for Sweden.

 Colombia

• Colombian Air Force

 Ecuador

• Ecuadorian Air Force

 Japan

• Imperial Japanese Navy Air Service

 Soviet Union

• Soviet Air Force

 Sweden

• Swedish Air Force

 United States

• United States Army Air Corps

No Ecuadorian aircraft survived as part the lend lease agreement with the U.S. which exchanged the Ecuadorian P-35s for P-47s. The P-35s were to be sold as scrap and the Ecuadorian government took the agreement literally. Within a few days of the delivery of the P-47s, ground crews with blow torches cut the P-35s apart and they were sold as scrap.^{[citation needed]}

AT-12

One of those who didn't make it to Sweden, recently restored back to flying condition at the Planes of Fame in Chino Airport, Los Angeles.

J 9

Exhibited in the Swedish Air Force Museum

J 9

Exhibited in the Kermit Weeks' Fantasy of Flight in Florida, presently undergoing restoration to flying condition.

P-35 (USAAC Serial no. 36-0404) displayed as a P-35A

On display at the National Museum of the United States Air Force, marked as the P-35A flown by the 17th Pursuit Squadron commander, 1 Lt. "Buzz" Wagner, in the Philippines, early 1941.

General characteristics

• Crew: One
• Length: 26 ft 11 in (8.2 m)
• Wingspan: 36 ft 0 in (11.0 m)
• Height: 9 ft 10 in (3.0 m)
• Wing area: 219.5 ft² (20.4 m²)
• Empty weight: 4,565 lb (2,070 kg)
• Loaded weight: 6,105 lb (2,770 kg)
• Max takeoff weight: 8,688 lb (3,940 kg)
• Powerplant: 1× Pratt & Whitney R-1830-45 Twin Wasp radial engine, 1,050 hp (783 kW)

Performance

• Maximum speed: 310 mph (499 km/h)
• Cruise speed: 260 mph (418 km/h)
• Range: 950 mi (1,530 km)
• Service ceiling: 31,400 ft (9,570 m)
• Rate of climb: 1,918 ft/min (9.74 m/s)
• Wing loading: 27.8 lb/ft² (136.0 kg/m²)
• Power/mass: 0.17 hp/lb (0.28 kW/kg)

Armament

2x 0.30 in machine guns; 2x 0.50 in machine guns; up to 350 lb (160 kg) of bombs

Notes

Bibliography

• Seversky P-35 Fact Sheet entry at the National Museum of the United States Air Force website (Access date: 31 December 2006)

Related development

• Seversky XP-41
• P-43 Lancer
• P-47 Thunderbolt

Comparable aircraft

• Fokker D.XXI
• Reggiane Re.2000 series
• PZL.50 Jastrząb
• Vultee P-66 Vanguard

Designation sequence

XP-32 - XP-33 - XP-34 - P-35 - P-36 - XP-37 - P-38

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