In May, 1956 PAF Conversion School Mauripur was split into Single Engine Conversion School and Transport Conversion Flight. The latter shifted to its new location at Lahore and was re-designated as No. 3 (Transport Conversion) Squadron on 1st July, 1957. Bristol Freighter was on the inventory of the squadron, and its function was to train all types of aircrew. On 20th September, 1959 the squadron moved permanently to Chaklala; it was reduced to number-plate basis on 1st July, 1963.

The Transport Conversion School was revived on 18th September, 1974; its first graduation was held on 15th July, 1975. The new building was inaugurated on 6th March, 1978. The school undertakes the training of Captains, Co-pilots, Flight Engineers and Navigators.