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The Boeing P-26 was the first all-metal production fighter and the first monoplane pursuit aircraft to enter service with the USAAC, but it was very much a transitional design, with its open cockpit, fixed landing gear and externally braced wings all belonging more to biplane era.
Like a surprising number of Boeing fighters, the P-26 was designed as a private venture, the Boeing Model 248. Work on the design began in September 1931, and on 5 December 1931 Boeing was rewarded with an Army Bailment Contract. The Army agreed to provide engines and instruments for three experimental aircraft with the designation XP-936. The Army would also test the aircraft, but they would remain Boeing property.
The new aircraft has a semi-monocoque fuselage (a similar design having been introduced on later models of the P-12/ F4B), and a low mounted wing with two spars and alight alloy cover. The wings were externally braced, with quite a web of cables, some connected to the fixed undercarriage, some to the upper fuselage and some to the tall radio transmitter mast. The fixed undercarriage was given streamlined fairings. The pilot sat in an open cockpit mounted above the wing, a great improvement on the position of the cockpit on the failed Boeing XP-9 shoulder winged monoplane.
Work on the Model 248 began in September 1931 and the first prototype made its maiden flight on 20 March 1932. The first prototype went to Wright Field for evaluation. When the USAAC decided to buy the aircraft it became the XP-26 and later the Y1P-26.
The second prototype went Anacostia for Navy trials then to Wright Field for static tests. On 25 April 1932 the third went to Selfridge Field, Michigan, for tests with operational squadrons.
On 14 June 1932 the Air Corps purchased the two XP-936s, which became the XP-26 (then later Y1P-26 and finally P-26).
The XP-936 had a top speed of 227mph at 10,000ft, 27mph faster than the P-12F biplane, which had a similar engine and a similar weight. The monoplane's biggest performance advantage was its climb rate, which rose by nearly 500ft/ min compared to the biplane.
On 7 November 1932 the Air Corps issued a specification for an improved version of the Model 248. This was followed by an order for 111 P-26As, placed on 28 January 1934.
Another 25 were ordered later, but were completed as P-26Bs or P-26Cs. The first of the production aircraft made its maiden flight on 10 January 1935. The production aircraft had an improved wing structure, floatation gear and a radio. Later on trailing edge flaps were added to reduce the aircraft's landing speed.
Service Record
As the P-26 entered service in 1934 it was used to equip entire units. First was the 1st Pursuit Group at Selfridge Field (17th, 27th and 94th Pursuit Squadrons). The 27th and 94th Squadrons kept the P-26 until 1938, the 17th until 1941. The P-26 soon became known as the 'Peashooter' in the Air Corps, where it was a popular aircraft because of its responsive controls.
Next was the 17th Pursuit Group (34th and 95th Squadrons). This group kept its P-26s for one year. It then became an attack group and passed its P-26s on to the 20th Group. Ironically the attack aircraft were slow to appear and the 17th ended up reverting to the P-12 biplanes it had used before 1934.
Third to gain the P-26 was the 20th Pursuit Group, based at Barksdale, Louisiana. Two of its squadrons (55th and 77th) got the P-26 in 1934, the 79th in 1934. The 20th kept the P-26 until 1938 when it converted to the Curtiss P-36 Hawk.
By the mid 1930s the P-26 was the standard air Corps fighter aircraft, and it was the fastest fighter in US service between 1934 and 1938.
Late in 1934 Colonel Henry 'Hap' Arnold tested the P-26 against the B-12, the newest fighters and bombers in the Air Corps. At this stage the advantage appeared to be with the bombers. Arnold came to the conclusion that it would be very difficult for a fighter aircraft to hit a bomber travelling at high speed, and in effect that the bomber would always get through. This was a fairly common view in the world's Air Forces in the mid to late 1930s, but Second World War experience would soon prove that deflection shooting at high speed was not as difficult as had been believed.
The P-26 took part in the air exercises of 1935, a simulated attack on Miami. They were judged to have been a great success, defeating the available bombers in a ten minute long simulated battle
The P-26 took part in the 1937 air exercises, which took place in California in May. The P-26s formed part of the defensive force for Los Angeles. They came up against the B-10, which was actually faster at high altitudes.
At the end of 1937 the 1st Pursuit Group converted to the Seversky P-35. The Curtiss P-36 Hawk soon followed the P-35 into service, and the P-26 began to the transferred to overseas bases. The first P-26s reached the Philippines early in 1937, followed by Hawaii and then the Panama Canal Zone. The P-26 was still the main fighter in these overseas departments in 1939, when there were two pursuit squadrons equipped with the type in Hawaii, two in the Panama Canal Zone and one in the Philippines.
The 24th and 29th Squadrons of the 16th Pursuit Group were the first to operate the P-26 in the Canal Zone, having them from 1938-39.
The 28th, 30th and 31st Squadrons of the 37th Pursuit Group (Canal Zone) received the P-26 in 1940. The 28th and 30th moved on after one year, but the 31st kept the P-26 until 1942, making it the last front line squadron to be equipped with the fighter,
The final group to get the P-26 in Panama was the 32nd Pursuit Group. Its 32nd and 37th Squadrons operated the type during 1941.
On Hawaii the 6th, 19th and 78th Pursuit Squadrons of the 18th Pursuit Group operated the P-26 at Wheeler Field in 1938-1941, but they had converted to the Curtiss P-40 Warhawk before the Japanese attack on Pearl Harbor.
The 3rd Pursuit Squadron operated the P-26 on the Philippines from 1937-1941. The 17th Pursuit Squadron had the P-26 from 1934 to 1941, and the 20th in 1940-41. They all became part of the 24th Pursuit Group in October 1941, by which time they had moved on to more modern aircraft.
The surplus P-26s were sold to the government of the Philippines. They were used by the 6th Pursuit Squadron of the Philippine air force and recorded some victories against the Japanese, including what was probably the first aerial victory of the campaign.
Variants
Boeing P-26A (Model 266)
The first production version was the P-26A, of which 111 were built. The P-26A was armed with two fuselage mounted 0.3in machine guns, and powered by a 600hp Pratt & Whitney R-1340-27 engine. The first production aircraft made its maiden flight on 10 January 1934 and they were all completed by 30 June 1934. Compared to the prototypes they had an improved wing structure, flotation gear and a radio. Later aircraft also had a higher headrest to protect the pilot if the aircraft rolled, installed after a pilot was killed when his aircraft rolled. Once in service the P-26As were given wing flaps to lower their landing speed, which dropped from 82.5mph to 73mph.
Boeing P-26B
The first two aircraft from the second order were completed as P-26Bs, and were powered by a fuel-injection Wasp R-1340-33 engine. They were also give the landing flaps that had been installed on the P-26A. They were delivered on 20 and 21 June 1934.
Boeing P-26C
The final twenty-third aircraft were delivered as the P-26C. This used the same -27 engine as the P-26A, but with minor changes to the fuel system and the carburettor, and with the ability to replace one of the 0.3in machine guns with a 0.5in machine gun. All of the P-26Cs were later given fuel injection systems to match the P-26B. They also had the landing flaps as standard. The first P-26C was delivered on 10 February 1936 and the last on 7 March 1936.
Model 281
The Model 281 was the export version of the P-26A. The first one made its maiden flight on 2 August 1934. It was given split type landing flaps to help reduce the landing speed on the smaller airfields found in the export market. The same type of flaps were later installed on American P-26s.
Boeing sold twelve Model 281s. One went to Spain and eleven to China, partly using funds raised amongst the Chinese community in the United States.
Twelve aircraft were completed as the export Model 281. Eleven went to China and one to Spain.
The first aircraft reached China on 15 September 1934 but was soon lost in a crash. The remaining ten aircraft saw combat against the Japanese, but were eventually grounded by a lack of spares.
Later on surplus P-26s went to Guatemala and to Panama.
Stats
Boeing P-26A (Model 266)
Engine: Pratt & Whitney R-1340-27 radial piston engine
Power: 500hp
Crew: 1
Span: 27ft 11.5in
Length: 23ft 7.25in
Height: 10ft 0.5in
Empty Weight: 2,197lb
Maximum Take-off Weight: 2,955lb
Maximum Speed: 234mph at 7,500ft
Cruising Speed: 200mph
Climb rate: 2,360ft/ min
Ceiling: 27,400ft
Range: 624 miles
Guns: Two 0.3in or one 0.3in and one 0.5in machine guns
Bomb load: Two 100lb bombs or five 30lb bombs