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Austin A.F.T.3 (Osprey)

Triplane Fighter Aircraft Prototype

The Austin Motor Company of Britain tried its hand at an in-house triplane fighter design as the Osprey - it lost to the Sopwith Snipe in competition.
Authored By: Staff Writer | Edited: 7/3/2018
National Flag Graphic


Year: 1918
Status: Retired, Out-of-Service
Manufacturer(s): Austin Motor Company - United Kingdom
Production: 1
Capabilities: Fighter; X-Plane;
Crew: 1
Length: 17.55 ft (5.35 m)
Width: 22.97 ft (7 m)
Height: 10.66 ft (3.25 m)
Weight (Empty): 1,102 lb (500 kg)
Weight (MTOW): 1,896 lb (860 kg)
Power: 1 x Bentley BR.2 rotary engine developing 230 horsepower and driving two-bladed propeller at the nose.
Speed: 118 mph (190 kph; 103 kts)
Ceiling: 19,029 feet (5,800 m; 3.6 miles)
Range: 354 miles (570 km; 308 nm)
Rate-of-Climb: 980 ft/min (299 m/min)
Operators: United Kingdom (cancelled)
Heading into 1918 during World War 1, there was already work being done to find a viable successor to the classic Sopwith Camel biplane fighter. The Camel appeared in June of 1917 and, by wartime standards, it lived a healthily long service life amidst changing technologies and tactics concerning the air war. The Austin Osprey, a single-seat triplane fighter - was developed with the hopes that it could follow the veteran design but it eventually lost out to the Sopwith Snipe - of which nearly 500 were produced from 1918 onward. For the Osprey, only a single prototype was ever made by the Austin Motor Company and the design quickly forgotten.

The original requirement was made by British authorities in 1917 (Specification A.1.A) calling for a single-seat, twin-gunned mount to succeed the venerable Camel. At this point in the war, the Austen Motor Company, like other concerns in British industry, were already helping in the war effort by producing other company's aircraft designs to meet demand. When the specification came down, Austen decided to try its hand in the design and development of a suitable fighter. The result was the A.F.T.3 "Osprey" of which three prototypes were ordered. Interestingly, engineers elected for a triple-wing arrangement over the standard two wings common to many fighters of the period.

On the whole, the Osprey utilized proven construction internally and out as well as traditional design techniques which did little to set it apart from the competition. Dimensions included a length of 17.6 feet, a wingspan of 23 feet and a height of 18.7 feet. Empty weight was 500 kilograms to a loaded weight of 860 kilograms. Power was served from a Bentley BR2 series rotary engine of 230 horsepower fitted to the nose and driving a two-bladed wooden propeller. Performance specs included a maximum speed of 119 miles per hour, a service ceiling of 19,000 feet and endurance up to three hours in the air. The triple-wing arrangement was all equal-span with a forward cant and parallel strut works.

Armament was the usual pairing of 2 x .303 Vickers machine guns in fixed, forward firing positions over the nose and synchronized to fire through the spinning propeller blades. Another interesting quality of the Osprey was the placement of a third machine gun, this being a Lewis Gun, set upon the center section of the middle wing assembly. Additionally this installation was trainable to an extent but its flexibility added little.

A first-flight of a prototype Osprey was had during February of 1918 as the war raged and testing followed into the coming weeks. As it stood, the Osprey simply could not compete, performance-wise, with the speedy, two-winged Snipe (fitting the same engine). Its three-winged arrangement created drag despite offering increased agility, this during a time when speed for fighter aircraft was the rule of the day. As such, the Osprey never advanced beyond the prototype stage and its two remaining prototypes were never built.


2 x .303 Vickers machine guns in fixed, forward-firing positions over the nose and synchronized to fire through the spinning propeller blades.

1 x .303 Lewis Gun in central wing assembly on trainable mounting.

Graphical image of an aircraft medium machine gun

Variants / Models

• A.F.T.3 "Osprey" - Base Series Designation; single prototype completed.
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