The P-30 was the production version of the Consolidated Y1P-25 two-seat monoplane fighter which in turn had evolved from the Lockheed-Detroit YP-24. It was the first aircraft to be built by Consolidated in its new factory at San Diego, California, after the company had relocated from Buffalo in 1935.
Based on tests with the Consolidated Y1P-25, a contract for four production examples (33-204/207) was placed by the Army on March 1, 1933. For some reason, the Army decided to give the production version of the Y1P-25 a completely different designation, and the P-30 number was next in line. Overall, the P-30 was quite similar to the Y1P-25 which preceded it, but was powered by a different engine, a 675 hp Curtiss V-1570-57 Conqueror with driving a two-blade constant-speed propeller. In addition, the undercarriage was simplified and the cockpit canopy was revised. At the same time, four similar A-11 attack versions (Ser Nos 33-308/311) were ordered. These A-11s were to be powered by V-1570-59 engines without superchargers, since high altitude performance was not considered important for an attack plane.
Tests of the first P-30 (33-204) began at Wright Field in January of 1934. Although the Army was generally pleased with the performance of the P-30 (especially with its high-altitude performance), pilots complained that the gunner who sat in a partly open cockpit was of limited value, as his position ensured that he would black out whenever maneuvering started. Maximum speed was 239 mph at 15,000 feet and 194 mph at sea level. Weights were 3832 lbs empty, 5092 lbs. gross. The P-30 could climb to 10,000 feet in 7.6 minutes. Range was 495 miles. Armament was two 0.30-cal machine guns in the nose, plus one flexible 0.30-cal machine gun operated by the gunner in the rear cockpit.
Three of the P-30s were issued in 1934 to the 94th Pursuit Squadron, stationed at Selfridge Field, Michigan. The fourth P-30 (33-205) was never issued to an operational unit.
Despite misgivings about the value of the second crewman, on December 6, 1934, 50 P-30As were ordered by the Army under contract W535-AC-7220. This contract was finalized on February 19, 1935. Serial were 35-001/050. These aircraft were redesignated PB-2A (PB for Pursuit, Biplace) before delivery. The engine which powered the PB-2A was the 700 hp Curtiss V-1570-61, with General Electric F-2H turbosupercharger. The PB-2A was equipped with a three-bladed controllable-pitch propeller. In addition, it carried oxygen for the crew, an absolute requirement for the altitudes at which the PB-2A was capable of operating.
The first production PB-2A came off the new line at San Diego and flew for the first time on December 17, 1935. The PB-2A had a maximum speed of 274 mph at 25,000 feet, 255.5 mph at 15,000 feet, and 214 mph at sea level. It could climb to 15,000 feet in 7.78 min. Service ceiling was 28,000 feet and range was 508 miles. Weights were 4306 lb empty, 5643 lbs gross. Armament consisted of two fixed 0.30-cal machine guns in the upper cowling synchronized to fire through the propeller arc, plus a single 0.30-cal machine gun operated by the gunner in the rear seat. In addition, the PB-2A could carry ten 17-pound fragmentation bombs.
Unfortunately, the first PB-2A crashed at Wright Field in late May. Nevertheless, the deliveries of the PB-2A built up quite rapidly, being completed by July 1936. The PB-2A initially served with the 27th Pursuit Squadron, 1st Pursuit Group at Selfridge Field, Michigan. A few were also operated by that group's 94th Squadron. In 1937, the 1st Pursuit Group converted to Seversky P-35s and their PB-2As were passed on to the 33rd, 35th, and 36th Squadrons of the 8th Pursuit Group based at Langley Field, Virginia. A few were also issued to the 60th Service Squadron at Barksdale Field, Louisiana.
On October 17, 1936, A PB-2A flown by Lt. John M. Sterling won the Mitchell Trophy race at Selfridge Field at a speed of 217.5 mph. In March 1937, a PB-2A reached an altitude of 39,300 feet over Langley Field and remained there for 20 minutes, but high altitude flights were seldom performed in practice because of the expense, inconvenience, and discomfort of the bulky pressure suits.
The PB-2A proved to be a sturdy aircraft, and there were relatively few fatal accidents. However, the retractable undercarriage of the PB-2A was a relatively new and unfamiliar innovation, and on numerous occasions pilots forgot to lower it before landing.
In the spring of 1939, the 8th Pursuit Group reequipped with the Curtiss P-36, and most of the 35 or so surviving PB-2As were transferred to Maxwell Field, Alabama. A few others were transferred to Eglin Field. By 1941, most were out of use. The last one was donated to a ground school in March of 1942. I don't know if any examples survive today.
Although the PB-2A was not exactly one of the shining lights in American aviation history, it nevertheless did chalk up an impressive list of firsts. The PB-2A was the only single-engined two seat monoplane fighter to attain operational status with the USAAC during the inter-war year, it was the first fighter in service with the USAAC to have a fully retractable undercarriage, it was the first fighter with a constant speed propeller, and it was the first truly successful application of a supercharger to an operational military aircraft. However, the two-seat fighter design concept was outdated by the time it appeared. The idea of defending the fighter against attack from the rear by stationing a second crew member in the rear cockpit never gained much support. The penalties entailed in terms of lost speed and maneuverability caused by the added load seemed to be too high a price to pay for the addition of just one more gun. Consequently, the service life of the PB-2A was quite short.
In 1936, the USAAC held a competition for a replacement for the Boeing P-26 fighter. Since the second crewman seemed to be the main drawback of the PB-2A, the Consolidated company thought that a single-seat version of their fighter might be successful in the competition. In April 1936, PB-2A Ser No 35-7 was converted by Consolidated to single-seat configuration and entered in the USAAC competition. It differed from the standard PB-2A in having the rear cockpit removed and the position faired over with a raised decking, but was otherwise quite similar to the PB-2A. Competitors were the Seversky SEV-1XP, the Curtiss Model 75, and the Northrop 3A. Unfortunately, flight tests revealed that the single-seat PB-2A fighter was still much too heavy in comparison to its competitors to make an effective fighter. And as if that wasn't enough, the single-seat PB-2A crashed during testing, which permanently doomed its chances. The ultimate winner of the competition was the Seversky design, which entered production as the P-35.
Some of the PB-2As serving with the Army were used for tests. PB-2A Ser No 35-26 was used to test a laminar flow aerofoil in 1940 with a new structure built over the existing wing.
The P-33 was a proposed version of the P-30 powered by a new Pratt & Whitney R-1830-1 radial engine. This project never got off the drawing board.
Sources:
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The American Fighter, Enzo Angellucci and Peter Bowers, Orion Books,
1987.
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General Dynamics Aircraft And Their Predecessors, John Wegg, Naval
Institute Press, 1990
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United States Military Aircraft Since 1909, Gordon Swanborough and
Peter Bowers, Smithsonian Institution Press, 1989.
- Singular Two Seater, Alain J. Pelletier, Air Enthusiast, Issue 85, 2000
