 As AI began to prove itself through early 1940 the RAF realised that the radar supply would soon outstrip the number of suitable aircraft available . With large numbers of single @-@ engine single @-@ seat aircraft already in the night fighter units , some way to fit these with radar was desired , and the Air Ministry formed the AI Mk . VI Design Committee to study this in the summer of 1940 . The resulting AI Mk . VI design was essentially a Mk . IVA with an additional system that automatically set the strobe range . With no target visible , the system moved the strobe from its minimum setting to a maximum range of about 6 miles ( 9 @.@ 7 km ) and then started over at the minimum again . This process took about four seconds . If a target was seen , the strobe would stick to it , allowing the pilot to approach the target using his C @-@ scope . The pilot would fly under ground control until the target suddenly appeared on his pilot indicator , and then intercept it . 
