A mate was on a task in a Chinook at an Range in the North of England repositioning some targets. They had JATE assistance as they were not your usual cleared loads. It was the end of the tasking day and they had to reposition an old Jet Provost. The load was lifted as normal and they departed to its new home.
The crewman was watching the load through the load hatch and looked away for a second to check the utility panel. When he looked back the load was nowhere to be seen - he looked through the window at the side of the aircraft to see the JP had decided it was not just a load, but, was an aeroplane again and was level with the chinook! The crewman jettisoned the load which flew its way down to make its own landing!