Slightly OT, but the Royal Flight used to apply the same half life principal to aircraft used for flying Royalty. We then had the mind boggling application of this "rule" when Chuck had to be transferred from a frigate (he was Guns 2, IIRC) to Eagle for lunch. Although 826NAS was less than 2 years into operating brand new Sea Kings, it was all too difficult to establish which of the fleet met the half life criteria.
End result? Bosun's Chair transfer at sea for the heir to the throne, with the same old bit of cable used to support the chair that had been used for the past 5 years. Not sure that was the best, but it got a bit of a laugh
Similar dramas when he learnt to fly in a Wessex V, "his" cab was kept especially for him, plus Dayglo panels all over for high vis. Prince Andrew obviously wasn't so important, routine cabs off the Flypro; especially in the Falklands
