Supermarine Seafire Mk.I

In late 1941, a total of 48 Supermarine Spitfire Mk Vb were converted by Air Training Service Ltd. at Hamble to become “hooked Spitfires”. This became the Seafire Mk Ib which was mainly used to allow the Royal Navy to gain experience in operating the Spitfire on aircraft carriers. The main structural change was made to the lower rear fuselage which incorporated an A-frame style arrestor hook and strengthened lower longerons. It was soon discovered that the fuselage, especially around hatches, was too weak for carrier operations. In an attempt to alleviate this condition, reinforcing strips were riveted around hatch openings and along the main fuselage longerons.

A further 118 Seafire Mk Ibs incorporating the fuselage reinforcements were modified from Spitfire Vbs by Cunliffe-Owen at Eastleigh and Air Training Service. These aircraft were equipped with Naval HF radio equipment and IFF equipment as well as a Type 72 homing beacon. In these and all subsequent Seafires the instruments were re-calibrated to read knots and nautical miles rather than mph and miles. The fixed armament was the same as that of the Spitfire Vb; two 20 mm Hispano Mk II cannon with 60 rounds per gun fed from a “drum” magazine and four .303 in Browning machine guns with 350 rounds per gun. Provision was also made to carry a 30 gal slipper fuel tank under the fuselage