It soon dawned on warplanners as World War 2 (1939-1945) ramped up that the far-reaching campaigns of the conflict would ultimately require equally-far-reaching aircraft in achieving total victory. This led to development of many powered and unpowered forms to help move man, machines and supplies from Point A to Point B. The General Aircraft "Hamilcar" was one of the unpowered contributors to the war effort (albeit on a limited scale), developed by the British and able to carry heavier-than-normal loads such as light-class combat tanks and similar vehicles.
The development of the Hamilcar coincided with the growth of the British airborne forces. Airborne elements, at their core, were forced to enter battle zones rather lightly-armed and with no armored vehicles in support. Lightweight artillery pieces became a traditional part of the inventory but these fighting forces really lacked the advantage of fighting alongside mechanized armor carrying powerful guns.
The British Air Ministry devised several specifications for its glider formations ranging from an 8-passenger form all the way up to the vehicle-carrying Hamilcar (Specification X.27/40). General Aircraft Limited was pushed to develop the aircraft for the latter role and, with that in mind, company engineers went to work and developed a large aircraft with a boat-hull and elevated flight deck. The wing mainplanes were high-mounted along the fuselage sides and a traditional single-finned tail unit was fitted. The fuselage was made purposely deep to accept the oversized loads intended. A wheeled undercarriage was used for ground running.
As completed, the Hamilcar featured a flight crew of two and could haul weight loads of up to seven tons. Its length was 68 feet with a wingspan measuring 110 feet and a total height of 20.2 feet. Empty weight was 18,400lb against a Maximum Take-Off Weight (MTOW) of 36,000lb. As the aircraft remained unpowered during its descent, its performance was limited by design and gravity. The listed "never exceed speed" was 187 miles per hour and descent was usually around the 150 mile per hour range. Stalling speed was 65 miles per hour.
The series received its designation of GAL.49 "Hamilcar" in 1941 and the prototype went airborne for the first time on March 27th, 1942. A smaller-scale version of the aircraft was earlier used for testing the design sound and this was known as the GAL.50. Before the end of 1942, some 10 pre-series aircraft were completed. The Hamilcar was then cleared for service that same year but problems (with both British military leadership and production logistics) meant that the series did not begin serious manufacture until the middle of 1943. Before the end of production in 1946 (the war ended in 1945), just 344 of the type were completed in all.
First-actions involving British forces and the Hamilcar were in Operation Tonga, the airborne and amphibious landings at Normandy (France). The Americans had become interesting the oversized gliders but the USAAF demand was such that General Aircraft could not fulfill it and the partnership came to naught. Future operations involving the glider were Operation Market Garden (A Bridge Too Far) and Operation Varsity (as part of Operation Plunder). Varsity marked the last combat use of the Hamilcar though the fleet continued in peace-time service with the British for a little time longer though, by the mid-1950s, all were out of circulation.
Variants of the line were non-existent though some were planned beyond the original Mark I form. This included the Hamilcar Mark X which was intended as a tropicalized combat glider, namely for the Pacific island-hopping campaigns against the Japanese. Modifications to the Hamilcar in this form included the addition of 2 x Bristol Mercury air-cooled radial piston engines to the wings to provide the aircraft (and its mothership) additional pull power. At least two prototypes were converted in this way and were found to be sufficient haulers. Despite some ten aircraft added to the stock, the war ended before these could be of any use to anyone.
Throughout its operational history, the Hamilcar glider remained solely in British service, this with the Army and Royal Air Force branches.