Originally Posted by
chevvron
So what happens when they use up the last of the 'ZZ's? Do they start using the myriads of 'never issued' serial numbers or maybe start again using 'AA' and 4 numbers?
Plenty of numbers left - they started allocating 'custom' numbers in the early 2000s and it's become a bit messy. - they were on ZK when they started ZZ, originally leased or UOR aircraft, then someone put the Wildcats in there. Now, rather than a straight linear progression, tail numbers are sometimes selected to suit the aircraft/fleet.