Anyone remember the VC10 practice display when OC Ops? missed the centreline and we watched as shockwaves formed over the wings and he trailed vapour as he attempted to heave it back onto the line... when it landed they refused to say how much over G it pulled but said it had pulled "some" and tried to keep it quiet, the meter in the cockpit having been reset. That left the only option open to us to do a full over G check on it, that took longer than a day so when the Aircraft availability stats went in it was listed as over G checks.. needless to say that got some attention in places up the line.