The Consolidated P-30 (PB-2) was a 1930s United States two-seat fighter aircraft. An attack version called the A-11 was also built, along with 2 Y1P-25 prototypes and YP-27, Y1P-28, and XP-33 proposals. The P-30 is significant for being the first fighter in United States Army Air Corps service to have retractable landing gear, an enclosed and heated cockpit for the pilot, and an exhaust-driven turbo-supercharger for altitude operation.
In 1931, the Detroit Aircraft Corporation, parent company of the Lockheed Aircraft Company, built a two-seat single-engined fighter aircraft based on the Lockheed Altair high-speed transport as a private venture. The prototype, the Detroit-Lockheed XP-900, flew in September 1931 and was purchased by the United States Army Air Corps as the Lockheed YP-24. It had impressive performance, being faster than any fighter then in service with the Air Corps, and an order for five Y1P-24 fighters and four Y1A-9 attack aircraft was placed for the new aircraft, despite the loss of the prototype on 19 October 1931.[1] [2] The Detroit Aircraft Corporation went into bankruptcy eight days later, however, leading to the cancellation of the contract.[1] [3]
When the Detroit Aircraft Corporation failed, the chief designer of the YP-24, Robert J. Woods was hired by Consolidated Aircraft.[3] Woods continued to develop the YP-24, the design becoming the Consolidated Model 25, with all-metal wings replacing the wooden wings of the YP-24 and with a larger tail. The Army Air Corps ordered two prototypes as the Y1P-25 in March 1932, to be powered by a Curtiss V-1570-27, fitted with a turbo-supercharger on the port side of the forward fuselage. The order for the second prototype was quickly changed to a Y1A-11 attack aircraft, omitting the supercharger.[4] [5]
First to fly was the Y1P-25, which was delivered to the Air Corps on 9 December 1932. It demonstrated promising performance, reaching a speed of 247mph at 15000feet, but was destroyed in a crash on 13 January 1933, killing its pilot, Capt. Hugh M. Elmendorf (whose name was later given to Elmendorf Air Base in Alaska).[4] [6]
The Y1A-11, armed with four forward-firing machine guns instead of the two of the Y1P-25 and racks for of bombs, was delivered to Wright Field on 5 January 1933. On 20 January 1933, the Y1A-11 disintegrated in midair, killing pilot Lt. Irvin A. Woodring.[7] Despite the loss of both prototypes in a week, on 1 March 1933, the Air Corps placed an order for four P-30 fighters and four A-11 attack aircraft. These production variants differed from the prototypes in having stronger fuselages, simplified undercarriages and more powerful engines.[3] [8]
The first P-30 was delivered in January 1934.[8] Testing showed that the gunner's cockpit was uncomfortable and cold at the high altitudes where the P-30 was intended to fight, while the rearward-facing gunners were liable to black out when the aircraft was maneuvered.[9] Despite these concerns, on 6 December 1934, the U.S. Air Corps placed an order for a further 50 P-30As, with more powerful V-1570-61 engines driving a three-bladed variable-pitch propeller and with oxygen supplies for the crew.[10]
Three of the four P-30s were delivered to the 94th Pursuit Squadron at Selfridge Field in 1934. The first P-30A, by this time redesignated PB-2A (pursuit, biplace), made its maiden flight on 17 December 1935, with deliveries to service units starting on 28 April 1936. The last of the 50 PB-2As were completed by August that year.
While intended as a high altitude fighter, the PB-2 flew relatively few high-altitude flights, partly because of the discomfort for the crew. One exception took place in March 1937, when a PB-2A was flown to 39300feet before being forced to return to lower altitudes when the aircraft's controls froze.[11] On 17 October 1936, a PB-2A flown by Lt. John M. Sterling won the Mitchell Trophy air race with a speed of 217.5mph.[12] Since the PB-2A was one of the few aircraft at the time to have retractable landing gear, they were frequently damaged in "wheels-up" landings when the pilots forgot to extend the landing gear.[13]
One PB-2A was modified to a single-seat configuration as the PB-2A Special, to compete in a 1936 Air Corps competition for a new fighter to replace the Boeing P-26 Peashooter. It was larger and heavier than the other competitors and was much more expensive. It crashed during testing, with the Seversky P-35 being ordered into production.[14] One A-11 was converted to the XA-11A testbed with the new Allison XV-1710-7 engine.[12]
While the PB-2 was sturdy,[13] the two-seat fighter concept was obsolete by the time the aircraft entered service,[12] and by 1939, all had been replaced in front-line service by Seversky P-35 and Curtiss P-36 Hawk aircraft. The survivors remained in use as training aircraft until after the start of World War II, with the last being withdrawn from use on 2 June 1942.[15]