YP-39 – test version
On April 27, 1939, the United States Army Air Corps (USAAC) placed an order for thirteen YP-39 prototypes. These prototypes were intended to serve as pre-production models for the P-39 Airacobra, providing an opportunity to refine the design before full-scale production. Here are the key details:
Development and Design:
- Supercharger Plans Canceled: Initially, one of the YP-39s was intended to be fitted with a supercharger and designated the YP-39A. However, this plan was canceled, and all thirteen prototypes were delivered without superchargers.
- Powerplant: The YP-39s were equipped with the Allison V-1710-37 engine, producing 1,090 horsepower.
- Serial Numbers: The Army serial numbers assigned to these aircraft were 40-27 through 40-39.
Armament:
- The first YP-39 prototype was delivered without any armament, but most of the remaining twelve were fitted with a combination of weapons:
- 1 x 37-mm cannon
- 2 x .50-caliber machine guns
- 2 x .30-caliber machine guns
- All these weapons were mounted in the nose of the aircraft, contributing to its combat capability but also adding significant weight.
Performance:
- Initial Flight: The first YP-39 took to the skies on September 13, 1940, and was handed over to the USAAC on October 12, 1940.
- Top Speed: Due to the added weight of the armament, the top speed of the YP-39 decreased further to 368 miles per hour at 15,000 feet, compared to the XP-39B.
- Climb Rate: The aircraft could climb to 20,000 feet in 7.3 minutes.
- Service Ceiling: The service ceiling was 33,300 feet.
- Range: The YP-39 had a maximum range of 1,000 miles, with a combat range of about 600 miles.
Characteristics:
- Wingspan: 34 feet
- Length: 30 feet, 2 inches
- Height: 12 feet, 10 inches
- Empty Weight: 5,042 pounds
- Gross Weight: 7,180 pounds
- Maximum Takeoff Weight: 7,235 pounds
- Fuel Capacity: 170 gallons
Appearance and Markings:
- The YP-39 prototypes were delivered with a natural metal finish, featuring national insignias on all four wing positions but none on the fuselage sides.
- The vertical tail and rudder were adorned with red, white, and blue stripes, as was standard for U.S. military aircraft during the late 1930s and into the early 1940s.
- The phrase “U.S. ARMY” was stenciled in large, flat black letters under the wings.