The mighty V force would have a trip carrying a 10,000lb inert bomb to simulate the instant sunshine of the time. This consisted of a big tin tube filled with concrete.
On this occasion there was a load thump in the back of the aircraft and the bomb aimer, checking his bombing equipment, realised that the inert had released itself and was sitting the bomb bay doors.
Not wishing to dig a big hole in the UK they were instructed to proceed to Wainfleet range and release it by opening the doors. The barge that was to be the target was identified on the NBS radar and in they came.
The bomb aimer had no idea of the ballistic characteristics of an inert; it was not something they published at the time, so he selected a bomb type 0, i.e. a perfect bomb.
He had the cross hairs on the target and with two minutes to go the bombing computer opened the doors.
They never did find out where it landed.