By the spring of 1926 the RAF was seeking a replacement for its Armstrong Whitworth Siskin and Gloster Gamecock biplane fighters, which between them equipped some 13 squadrons at home.
Accordingly, the Air Ministry issued Specification F.9/26 for a single-seat day and night fighter in April that year, stipulating metal construction and an air-cooled radial engine.
The promise of a contract for the RAF’s next-generation frontline fighter was highly attractive and a no less than nine aircraft manufacturers submitted designs to the Specification. Among them was Hawker, which was quick off the mark with its Hawfinch and was the first of the F.9/26 submissions to fly in March 1927.
Hawker Chief Designer Sydney Camm developed a two-bay biplane with sharply staggered wings of uneven span. It was an all-metal construction with fabric covering using the system patented by Hawker, first adopted in the company’s experimental Heron of 1925.
Initially powered by a Bristol Jupiter VI radial engine, this was replaced within a few months by a Jupiter VII of 450 hp.
Having completed its manufacturer’s trials, the prototype (J8776) was sent to the Aeroplane & Armament Experimental Establishment (A & AEE) at Martlesham Heath in July 1927 for performance and handling trials, spending ten days undergoing deck-landing trials aboard HMS Furious.
The Hawfinch earned praise from the pilots that flew it during these trials and after further company trials at the end of 1927, the machine was once again back at Martlesham Heath for further evaluation, this time in the company of its F.9/26 competitors.
In May 1928, the Hawfinch (J8776) was flown by pilots of No 1 Sqn in trials against its nearest rival the Bristol Bulldog and that June saw it participate in the RAF Display at Hendon, wearing New Type No 3.
Trials continued at various RAF squadrons for the next few months with the competition having narrowed to the Bulldog and Hawfinch. The former ultimately won out, having a fractionally higher top speed than the Hawfinch.
The Bristol design was awarded the contract whilst the Hawfinch was returned to Hawker in September 1928. They fitted it temporarily with single-bay wings and floats for further trials at the Marine Aeroplane Experimental Establishment at Felixstowe.
Later re-fitted with wheels and two-bay wings, the Hawfinch was returned once again to Hawker ownership, being allocated a civil registration (G-AAKH) although it is thought that it never wore these markings as the registration was never officially taken up.
The Hawfinch missed its chance to become the RAF’s definitive frontline fighter for the late 1920s and early 1930s although the sole prototype went on to become an invaluable research aircraft. It played an important role as an aerofoil-investigation machine, serving with the Royal Aircraft Establishment (RAE) at Farnborough until late 1933.
It was then returned to Martlesham Heath for a final series of handling trials with No 22 Sqn after which it was scrapped.
Variants & Numbers
Only one example, J8776, was built.
|Powerplant||One 450 hp Bristol Jupiter VII nine-cylinder air-cooled radial engine driving Watts two-bladed wooden propeller; also fitted with 1 x 455 hp Jupiter VI and 400 hp Armstrong Siddeley Jaguar V|
|Span||Two-bay wings 33ft 6in; Single-bay wings 31ft 3in|
|Maximum weight||Jupiter VII engine, two-bay wings, wheel undercarriage: 2,910lb|
|Capacity & Armament||Single pilot; Two fixed forward-firing Vickers machine-guns, provision to carry four 20lb bombs under the wings.|
|Maximum speed||171 m.p.h. at 9,850 ft|
The sole Hawfinch J8776 was scrapped at the end of 1933.