YO-55 ercoupe in the military

A few were owned by the CAA as transportation and used in the civilian pilot training program. It is possible the CAP used them for spotting but I don’t know. The Ercoupes major role was as the test bed for JATO. It was used to test JATO technology and was the first US aircraft to take off with JATO and the first US aircraft to take off under rocket power.

what was the ercoupe used for in the military, I read somewhere it was used to spot German subs, is this true?