When I went through Shawbury in the late '80s we were forbidden from doing any FW flying whilst on RW training, even as Crewman.
I don't think we were banned from powered FW flying while on 705, but I know we were not allowed to go gliding. A 705 boy was on late finals in a glider, a bit low, so he reached for the lever on his left and pulled it up. Not surprisingly the glider dropped even shorter, and straight into a Cornish hedge, which you may know is mostly earth/stone bank. Sadly he did not walk away.