Two of the 25 aircraft added to the initial P-26A order (Ser Nos 33-179,180) were completed as P-26Bs. They differed from the P-26A in being fitted with 600 hp Pratt and Whitney SR-1340-33 fuel injected engines. The attendant revisions to the fuel system, plus the fact that the P-26Bs were the first P-26s to be built with wing flaps as original equipment, justified a change in factory model designation to Model 266A.
By 1930s standards, the P-26A was a "hot" ship. Its 70-knot landing speed made it difficult to handle and relatively unforgiving on landing. 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.
The first flight of a P-26B was on January 10, 1935. The first P-26B was delivered to the Army on June 20, 1935, the second on June 21. The use of fuel injection rather than carburetrors caused some minor changes in the weight and center of gravity of the aircraft.
The cost of a P-26B was $14,009, less the engine and government-furnished equipment.
Serials of P-26B: 33-179, 33-180.
Specification of Boeing P-26B:
One Pratt and Whitney SR-1340-33 Wasp nine-cylinder supercharged air-cooled radial engine with fuel injection rated at 500 hp at 7500 feet. Performance: Maximum speed 235 mph. Range 635 miles. initial climb rate 2360 ft/min. Service ceiling 27,000 feet, absolute ceiling 28,000 feet. Weights: 2302 lbs empty, 3062 lb gross. Dimensions: Wingspan 27 feet 11.6 inches, length 23 feet 9 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.