Before service testing on the XP-936 were completed, the Army decided to go ahead with production of the design in an improved form. On November 7, 1932, the Army issued a new specification for a fighter which incorporated the best features of the Model 248 with the improvements found desirable during the test program. On January 11, 1933, USAAC ordered 111 examples under the designation P-26A. Serials were 33-28/138. It beat out the competing Curtiss XP-31 Swift for production orders. This initial order was soon increased to 136, with the additional planes being completed as P-26B and P-26C. This was the the largest order placed for a single aircraft type since the Boeing MB-3A of 1921.
The first P-26A made its maiden flight on January 10, 1934, and the last aircraft of the initial order for 111 aircraft was delivered on June 30, 1934. The factory designation of the P-26A was Model 266. The unit price per plane (less engine and government- furnished equipment such as armament, radio, etc) was $9999, compared with $10,197 for the P-12E biplane which it replaced. This must have been one of the few occasions in history in which a new military aircraft was actually cheaper than the one which it superseded. :-)
The powerplant of the P-26A was a single Pratt and Whitney R-1340-27 Wasp nine-cylinder supercharged radial engine rated at 500 hp at 7500 feet. It drove a Hamilton-Standard two-blade, adjustable-pitch propeller. The armament was the same as that of the prototypes, namely a pair of 0.30-in machine guns, or one 0.30 and one 0.50-in machine guns, mounted in the fuselage sides and firing through the spaces between the cylinder heads of the radial engine. Outwardly, the P-26A differed from the prototypes only in that the wheel pants did not project aft of the undercarriage strut fairings. In addition, the wingtips were elliptically shaped which gave the wings sightly larger wingspan but slightly less wing area. Inwardly, the P-26A wing structure was considerably revised and a radio was added. The addition of the radio was reflected in the fitting of an antenna mast on the starboard fuselage just ahead of the cockpit and a mast on top of the vertical tail.
Originally, the P-26As had the low streamline headrests of the prototypes. On February 22, 1934, Lt. Frederick I. Patrick of the 20th Pursuit Group at Barksdale Field, Louisiana made a forced landing during a routine flight and his aircraft (33-46) flipped over on its back. Although the mishap inflicted only minimal damage to the aircraft, Lt. Patrick's neck was broken and he was killed. In order to prevent any more fatalities of this nature, the headrest was increased in height by eight inches. Delivery of later production machines was delayed until this modification was completed. The first aircraft on the production line to receive the new headrest was 33-56, and those already flying were retrofitted with the new headrest in the field.
While the P-26A was coming off the production line, the Army decided that it wanted emergency flotation gear fitted. 33-51 became a test bed with two manually-activated flotation bags installed in a streamlined fairing above each wing stub. The system was installed on aircraft from P-26A 33-53 onward, but was not retrofitted to the earlier aircraft. There is no record that any P-26As were saved by this system--in fact, at least one P-26A was lost in a fatal accident when one of the flotation bags inadvertently inflated in flight.
After the P-26As were in service for a short time, the Army became dissatisfied with the relatively high landing speed of 82.5 mph. Wing flaps were developed and tested by the Army on a P-26A and by Boeing on the Model 281, the export version of the P-26A. These brought the landing speed down to 73 mph. Boeing then retrofitted these flaps to all P-26As then in service and also added them on all the P-26Bs and Cs still in the factory.
Serials of Boeing P-26A: 33-28/138
Specification of Boeing P-26A:
One Pratt and Whitney R-1340-27 Wasp nine-cylinder supercharged air-cooled radial engine rated at 500 hp at 7500 feet. Performance: Maximum speed 234 mph. Range 635 miles. initial climb rate 2360 ft/min. Service ceiling 27,400 feet, absolute ceiling 28,300 feet. Weights: 2197 lbs empty, 2955 lb gross. Dimensions: Wingspan 27 feet 11.6 inches, length 23 feet 7.25 inches, height 10 feet 0.38 inches, wing area 149.5 square feet. Armament: One 0.50-in, one 0.30-in machine guns, or two 0.30-in machine guns mounted in the fuselage sides firing through the engine cylinder banks. Racks were provided under the fuselage for five 30-lb bombs or two 100-lb bombs.