Air Ministry Specification O.22/26 called for a shipboard aircraft combining fleet spotter and fighter aircraft capabilities. Submissions for the requirement therefore combined the maneuverability needed for dog-fighting with good low speed characteristics necessary for deck operations. Additional features demanded was the ability to be catapult launched, have folding wing capability (to achieve demanding dimensional requirements) and to be able to operate successfully when required as a floatplane all made this a very demanding design challenge.
Power was to be provided by a Rolls-Royce Falcon XIIMS twelve-cylinder liquid-cooled engine.
After initial evaluation, prototype contracts were placed for two Short Gurnards and one each of the Blackburn Nautilus, Fairey Fleetwing and a naval adaptation of the Hawker Hart known as the Hawker Osprey.
The Blackburn Nautilus design had a long slim nose with the coolant radiator between the lower fuselage and the upper surface of the bottom wing. Armament comprised a fixed forward-firing Vickers gun on the port side and a ring-mounted Lewis gun operated from the rear cockpit.
The Nautilus (N234) flew for the first time at Brough Aerodrome in May 1929 but soon encountered handling and cooling problems. These resulted in the fitting of an elevator of reduced chord and a modified radiator compartment. As a result, the constructor’s flight trials were not resumed until 21st August 1929 and Evaluation and Competitive Trials at Martlesham Heath followed shortly afterwards.
Despite a relatively good showing at Martlesham Heath, the Nautilus was unsuccessful in the main competition and the aircraft (N234) was transferred to Gosport on the South Coast where it was joined by the Fairey Fleetwing and the Naval Hart prototype, forming 405 Flight Fleet Air Arm .
The move to Gosport took place at the beginning of November 1929 and after a short time operating from HMS Furious, the Nautilus was modified for use as an unarmed three-seat communications aircraft.
Eventually the Osprey was adjudged successful and H.G.Hawker received the eventual production contract.
The Nautilus was subsequently returned to Martlesham Heath and continued to operate throughout 1932 as a communications aircraft. It continued in service until January 1933 and its last recorded flight was from Martlesham to Farnborough (and return) on 26th January 1933.
Variants & Numbers Built
One prototype only, serial number N234.
|Powerplant||One 525 hp Rolls-Royce F.XIIMS twelve cylinder liquid cooled engine|
|Span||37 ft 0 in|
|Maximum Weight||4,750 lb|
|Capacity & Armament||Two crew; one fixed forward-firing Vickers machine guns and one defensive Lewis gun operated from the rear cockpit|
|Maximum Speed||154 mph at 5,000 ft|
Nil, withdrawn from use in early 1933.