Beginning in January 1944, training exercises were conducted carrying the Tetrarchs and their crews inside Hamilcar gliders. These exercises were successful; during the training by 'C' Squadron of the Glider Pilot Regiment, which specialised in flying the Hamilcars, over 2,800 lifts were made with an average of 50 lifts per crew. Only three incidents resulted in fatalities or injuries, with seven pilots killed during the training. When the Tetrarch was re-designated as an airborne tank, several changes were made to its design. A number of tanks had their 2 pounder guns replaced with a infantry support howitzer; these tanks were then designated as Tetrarch 1 CS (Close Support). Additionally, Littlejohn adaptors were added to those Tetrarchs which still possessed their 2 pounders to increase their muzzle velocity and armour penetration.