Boeing XP-7

The Boeing XP-7 was a prototype United States biplane fighter of the 1920s.

Development and design

The XP-7 started life as the last Boeing Model 15 (PW-9D), serial 28-41. It was then adapted to mount the 600 hp Curtiss V-1570 Conqueror engine. Labelled by Boeing as their Model 93, the XP-7's nose was shorter and deeper than that of the standard PW-9, and the craft was 75 pounds lighter overall.

It first flew in September 1928 and did well, with a 17 mph speed increase over the PW-9. However, despite a proposal to build an additional four P-7s, the design was at the very limits of its capabilities and somewhat outdated even by the time of its first flight. At the end of testing, the Conqueror engine was removed and the aircraft converted back into a PW-9D.

Operators

Specifications

Data from

General characteristics

United States military aircraft designation systems

The United States Military Aircraft Designation System was first designed in 1919 when the US Army's Aeronautical Division became the United States Army Air Service. Before this aircraft were put into service under their manufacturers' designations.

History

United States Army Air Service 1919 to 1924

During this period Type Designations used by the United States Army Air Service were allotted, using two or three letters, which were an abbreviation of the aircraft's purpose. Examples include GA for Ground Attack aircraft; NO for Night Observation aircraft and NBS for Night Bombardment, Short Distance aircraft.

Army aviation 1924 to 1962

From 1924 to 1947 the Air Service, United States Army Air Corps, United States Army Air Forces and United States Air Force used a designation system based on mission category, with each model in a category numbered sequentially. In 1947, the designation system was extensively overhauled, with several categories being dispensed with, and others renamed For instance, the Lockheed P-80 Shooting Star (Pursuit) was redesignated as F-80 (Fighter), while the A-26 medium bomber/attack aircraft was redesignated as the B-26, reusing the designation, the Martin B-26 having retired in the meantime.