IIRC the tarmac outside the mess at Coltishall had a permanent concrete patch amongst the tarmac for piano burning.
An abiding memory is John C***sham with his love of black powder and cannons. Biscuit tins bolted to the underside of the main table and detonated by wire amongst others.
The reception at West Drayton where the lift from the accommodation above opened directly opposite the desk. At a moment when full of dignitaries a ding of the lift arrival. All watch as the door opens to reveal a lone cannon on the floor with the fuze smoking - a loud bang ensues and reception fills with black smoke - the door shuts and the lift retreats back to the floors above....
Buchan - a crew life raft borrowed from LM concealed below the carpet under the top table with a hose to an air bottle under the bottom table. At a moment during desert there is a hiss and the individual tables start to rise and lift like Tower Bridge with the execs vainly grabbing and holding onto their plates and the mess silver as it inexorably starts sliding to the far ends and the floor.