The United States Army Ordnance Department was asked to produce this replacement, which in turn selected Marmon-Herrington to design and build a prototype airborne tank in May 1941.

Marmon-Herrington only began to produce significant numbers of the T9 in late 1943 and early 1944, and by then the design was considered to be obsolete; only 830 were built by the time production ended in February 1945.

The tanks were forced to withdraw from the position after several hours however, because they attracted artillery fire that caused the infantry to suffer heavy casualties.

[5] At the time the request was made, the War Office considered using the equipment in Britain's fledgling airborne forces, which had been formed in June 1940 by order of the Prime Minister, Winston Churchill.

[6] When officials at the War Office examined the equipment that would be required for a British airborne division, they decided that gliders would be an integral component of such a force.

In a conference held on 16 January 1941, it was decided that the General Aircraft Hamilcar, under development at the time, would be used to transport a single tank or two Universal Carriers.

[8] A decision had recently been made by the War Office that light tanks were no longer to be generally used in the British Army; on the whole they had performed poorly during the Battle of France and were considered to be a liability.

[10] The War Office was also aware that the tank had a faulty cooling system that made the Tetrarch unsuitable for service in hotter climates, such as the Middle East and North Africa.

[12] The United States Ordnance Department was given the task of developing the proposed tank, and in turn requested designs from three American companies: General Motors, J. Walter Christie and Marmon-Herrington.

[17] Some 25 Locusts were ordered in April 1944 for use in the European Theater of Operations, and delivered by September; although a small number were sent to the United States Sixth Army Group in Alsace, France, for testing, they were never used in combat.

[20] Extensive testing of the M22 occurred in 1943 and 1944, and was conducted by both the Ordnance Department and the British Armoured Fighting Vehicle (AFV) Gunnery School at Lulworth Ranges.

[16] The AFV School noted that the process of loading the M22 into a C-54 transport aircraft took considerable time and involved the use of complex equipment.

[21] A heavy transport aircraft, the Fairchild C-82 Packet, was developed to specifically carry the M22 inside its fuselage and unload it through a set of clam-shell doors, but it did not enter service until after the war had ended.

[22] The US Army Armored Board released a critical report on the Locust in September 1943, stating that it was inadequate in the areas of reliability and durability, and indicating that it would not be able to be successfully used during airborne operations.

[16] Similarly a report made on 13 March 1944, by elements of the 6th Airborne Armoured Reconnaissance Regiment complained that when a high-explosive shell was fired from the gun, the resulting shell-burst was so weak that observers had difficulty in seeing where it impacted.

However, records indicate that by April the Hamilcar gliders of the regiment were being refitted to only carry Tetrarchs, and by late March the Locusts appear to have been completely replaced.

[32] However, due to their thin armor and underpowered armament they proved to be completely outclassed by the tanks and self-propelled guns deployed by German forces, such as the Panzer IV and the Sturmgeschütz III.

[34] In September the division returned to Britain and in the first week of October 1944, the 6th Airborne Armoured Reconnaissance Regiment underwent an extensive reorganization.

Weather conditions for the operation were excellent, with clear visibility, and all eight gliders arrived in the vicinity of the landing zone without incident.

[38] During their attempts to land, however, the small force was severely depleted; one glider broke away from the Halifax towing it and disintegrated, apparently as a result of structural failure, with the Locust inside it falling to the ground.

[39] Three more gliders came under heavy German anti-aircraft fire and crashed as they landed; one tank survived with a damaged machine gun, another crashed through a house which put its wireless radio set and main armament out of action, and the third broke loose of the glider as it landed and was flipped over onto its turret, rendering it useless.

[41] Of the four Locusts that reached the rendezvous point, only two were undamaged and fully fit for action; these two were immediately deployed to the high ground east of the Diersfordter Wald, while being covered by the two damaged tanks.

Upon arrival they were engaged by German troops and had to be supported by an infantry company, and soon their presence began attracting a great deal of artillery and anti-tank fire.

[45] The 3 June 1946 issue of Life magazine has a five-photo article about Kamiel Dupre, an Illinois farmer who bought two surplus Locusts for $100 each from the Rock Island arsenal.

Intending to use one as a farm tractor and one for spare parts, Dupre found the vehicles to be in poor condition and difficult to use and maintain.