 While aircraft were being delivered , Bowen , Tizard and Watt pressed the Air Ministry to appoint someone to command the entire night fighting system , from ensuring aircraft delivery and radar production to the training of pilots and ground crew . This led to the formation of the Night Interception Committee ( so @-@ named in July 1940 ) under the direction of Richard Peirse . Peirse raised the Night Interception Unit at RAF Tangmere on 10 April 1940 ; it was later renamed the Fighter Interception Unit ( FIU ) . 
