Basically BAA appears to have broken the terms of the original 1953 lease by selling a section of 21/03 off to their property arm. Luckily Mathew Hudson and Alan Macdonald (Bae) got together and uncovered the original lease and with Bae needing the secondary runway for the Flying College and for Jetstream development and demos, the two of them together, forced BAA's arm and they reluctantly sold to Mathew Hudson, thus reinstating 21/03's full length.