I refer to the letter from Elsie Tu headlined 'Amazing account' (South China Morning Post, April 19).
Mrs Tu asked how the 24 crew on board the US spy plane could have escaped injury when the plane 'went out of control'.
Perhaps Mrs Tu is not aware of seat belts.
The next time she sees the inside of an aircraft, she might like to examine the two strips of (usually) brightly coloured nylon on her seat, each with a shiny bit at the end.
These miraculously lock together, making a very effective restraint for keeping one firmly in one's seat.
A marvellous adaption of this device is (I believe) installed on all flying machines for the benefit of essential persons such as the crew.
Their restraint systems are even more effective, having shoulder and crotch straps in addition to the lap fastening.
I hazard that this is may be the cause of the 'aviation history' to which Mrs Tu refers.
I hope this explains the mystery.