well many of us can remember the pre-extension days, with a useable distance of under 5000 foot, I think LDA on 15 was about 4600 and TODA on 33 was 4800. Even a F27 was significantly weight restricted on 33 departure, so the operation of 737-2 to Spanish destinations was at the limits of the aircraft, as you could imagine..... and the pioneering airline was ironically Britannia.