 By this point , supplies of the Beaufighter and the new Mosquito had improved dramatically , and the decision was made to remove all single @-@ engine designs from the night fighter force during 1942 . Two Defiant units did switch to the Mk . VI , but they operated for only about four months before converting to the Mosquito . Production for the AI role ended , and the electronics were converted to Monica tail warning radars for the bomber force , until the mid @-@ 1944 knowledge of the Germans ' Flensburg radar detector , which spotted Monica transmissions , was revealed to the British . 
