From todays Guardian diary:-
This popped up on the MoD's Freedom of Information website in response to a query. "You asked how many pianos have been destroyed by fire or so called 'high spirits' at each RAF station since January 2000 ... I can confirm that we do not hold any information that indicates that pianos have been destroyed by fire or so called 'high spirits' ... That said, I am aware from anecdotal evidence that this activity does occur on occasion. However, I can reassure you that any pianos which may have been destroyed in this manner would have been paid for privately."
(Last weekend a friends son got married, the bride being in the RAF and the groom in the Army. On the evening before the wedding they had a barbecue in the local pub for the guests who were staying overnight. I did mention to the grooms father that it must have been a quiet do since no-one had set fire to the pub piano).