de Havilland DH.77

History

In 1927, the Air Ministry finalized its F.20/27 specification, which was designed to create a light single-seat interceptor with a good rate of climb. This specification took over the early 1926 F. 9/26 regular order, which called for "day and night zone fighters". Among the defenders who responded - Armstrong Whitworth, Bristol, Fairey, Hawke, Sanders, Vickers and Westland - de Havilland became historic focus point.

The company produced the "DH. 77", a monoplane attributed to W.G. Carter and Major F.B. Halford. The first flight of the aircraft was recorded on July 11, 1929.

The final product looks elegant by late 1920s standards. The fuselage is slim and, where possible, aerodynamically improved. The engines are mounted in the nose in the usual way, while traditional single-tail aircraft are arranged in the tail.

The wing main aircraft is straight, mounted low and slightly forward amidships. A one-seat open-air cockpit was also placed forward in the center of the fuselage. Compared to modern biplanes, the aircraft offers pilots significantly improved cockpit visibility due to the lower setting of the monoplane wings. The landing gear was fixed, rolled on two main components, and had a "trail" arrangement (tail rails were used to pull the tail up).

The listed curb weight is 1,655 pounds, while the MTOW is 2,300 pounds.

Dimensions include a length of 24.4 feet, a wingspan of 32.1 feet, and a height of 8 feet. Inside, the light fighter is powered by a Napier H-series "Rapier I" 16-cylinder air-cooled engine that produces 300 horsepower and drives a twin-blade propeller unit.

Of note is the supercharged state and flat design of the engine. Performance specs include a top speed of 205 mph, a service ceiling of up to 26,000 feet and a rate of climb of 1,885 feet per minute (and the interceptor's most important attribute).

As a military-aware interceptorthat is, an aircraft responsible for repelling an incoming air threat head-on for a short period of timeDH. The 77's armament consisted of a typical mount of 2 x .303 caliber Vickers machine guns, firing synchronously from the nose section via rotating propeller blades.

These guns were mounted on fixed forward-firing mounts.

According to The Times, the plane was done in "hybrid construction", i.e. metal, fabric and wood adapted to its shape. The wings are fitted with two internal steel beams for the required strength and are further supported by wooden ribs. The entire surface of the plane is then covered with fabric.

The fuselage features a tubular steel frame surrounded by typical wooden ribs and covered with a fabric skin.

The aircraft only completed a flying prototype, and the Air Force (via direct purchase) went through the usual test program to see what they had - and what could be squeezed out of the full design. The only copy survived the official program, but was eventually passed on.

The stand-up interceptor requirement was later fulfilled in the framework of the classic Hawker "Fury" biplane (detailed elsewhere on this page) and the DH. The 77 continued to be used as a Napier engine test bed until its time officially expired in the mid-1930s.

Specification

Basic

Production

Roles

Dimensions

Weight

Performance

PERFORMANCE

ARMAMENT

VARIANTS