Farnborough Saab 105
I think this was 1974.
I saw this happen.
The Saab 105 did a "touch and go" over the top and in front of the Viggen that was lined up for take off. The Viggen took off while the 105 did a loop.
On coming out of the loop the pilot forgot to extend the gear and the 105 landed on its belly. It stayed wings level until it stopped and then tipped onto one wingtip.
The aircraft was removed with a crane and Queen Mary and the runway was re opened within 15 mins, while the Viggen did an extended display.
My father was at the show the following day and the Saab 105 was flying again with the announcer telling the crowd what had happened and what a good aircraft it was.
Hope this helps.