First flown on 4 January 1940, there was no prototype as such for the Fulmar, which was evolved in 1939 from the P.4/34 lightweight develop-ment of the Fairey Battle day bomber. The urgent need by the Fleet Air Arm (FAA) for a new fighter led to a rapid trials programme, beginning on January 4, 1940, with the maiden flight of N1854, the first production Fulmar, of which 250 were ordered. The Fulmar I was an all-metal cantilever monoplane, with folding wings for carrier stowage; the semimonocoque fuselage housed the deck arrester gear and catapult points, and space was provided for an inflatable dinghy.
The pilot's cockpit was separated from that of the observer/navigator, and both were enclosed by perspex canopies following the contours of the fuselage. The wide-track undercarriage retracted inwards towards the wing roots. The powerplant for all except two early Fulmar 1 aircraft was the 1080-hp Rolls-Royce Merlin VIII engine. Due to the additional weight of a second crew member, and the special equipment required for carrier operation, the Fulmar did not achieve the same rate of climb or airspeed as its land-based counterparts - although this was not necessarily required by the Royal Navy. Armament was very similar to the best in the RAF, consisting of eight 0.303-in (7.7-mm) Browning machine-guns-four in each wing with twice the ammunition capacity of the Spitfire and Hurricane. The lack of a rear defensive gun was one of the Fulmar's principal deficiencies, and some crews unofficially fitted an additional gun of their own choice in the rear cockpit.
Deliveries of the Fulmar I began in June 1940, to 806 Squadron, and it became opera-tional aboard the aircraft carrier Illustrious about two months later. A total of 250 853kW Rolls-Royce Merlin VIII-powered Mk Is were built. At this time, Fairey had plans for the development of the Fulmar II, to be powered by the 1300-hp / 969kW Merlin 30, and with weight reductions brought about by the use of lighter constructional materials. This enabled the Fulmar II to carry the originally-intended bombload in the form of a single 113.4-kg (250-1b) or 227-kg (500-1b) bomb beneath the fuselage (the Mk I being limited to eight 9-kg [20-lb] or 11.3-kg [25-lb] bombs under the wings). The Fulmar Mk II with nearly 300 more horsepower, was only 16km/h faster than the Mk I.
Orders for 350 Fulmar IIs were placed during the autumn of 1940, bringing the total number on order to 600. With conversions to Fulmar II beginning on the Mk I production line, the eventual result was that well over 400 were completed as Mk IIs. Ammunition capacity of the Fulmar II was eventually increased from 750 to 1000 rounds per gun but, despite this, the aircraft's fighting ability was still disappointing. Although short on speed and manoeuvrability, it served with 14 FAA squadrons, accounting for more than 100 enemy aircraft until the appearance of more advanced types such as the Seafire and Firefly. During the summer of 1941, four 0.3-in (12.7-mm) machine-guns were fitted to one Fulmar. Firing trials proved satisfactory, and the last 100 aircraft were adapted for such an armament, but not all were equipped due to an insufficient supply of the heavier guns. Fulmars were used quite successfully as convoy escorts during the mid-war years, and about 100 were converted into makeshift night fighters. In 1943 they were gradually withdrawn from front-line service and reassigned to training duties.
Fairey Fulmar Mk.I
Engine: 1 x Rolls-Royce Merlin VIII, 805kW / 1065 hp
Max take-off weight: 4853 kg / 10699 lb
Empty weight: 3955 kg / 8719 lb
Wing loading: 31.37 lb/sq.ft / 153.0 kg/sq.m
Wingspan: 14.14 m / 46 ft 5 in
Length: 12.24 m / 40 ft 2 in
Height: 4.27 m / 14 ft 0 in
Wing area: 31.77 sq.m / 341.97 sq ft
Max. speed: 215 kts / 398 km/h / 247 mph
Service ceiling: 6555 m / 21500 ft
Endurance: 4 h
Armament: 8 x .303in / 7.7mm machine-guns
Bombload: eight 9-kg [20-1b] or 11.3-kg [25-1b] bombs
Fairey Fulmar Mk.II
Engine: 1 x Rolls-Royce Merlin 30, 1300-hp / 969kW
Span: 14.13 m (46 ft 4.5 in)
Length: 12.24 m (40ft 2 in)
Gross weight: 4695 kg (10350 lb)
Maximum speed: 417 km/h (259 mph)
Bombload: 113.4-kg (250-1b) or 227-kg (500-1b) bomb