The B 757 requires shorter runway lengths for equivalent payloads and flight lengths. The DFID did not specify the short runway length, it was the maximum they could build without huge additional costs. The killer was the certifying agency ASSI insisting on 300 meter RESAs reducing a 6397 ft. pavement to as little as 5036 ft. landing length. All flight planning to HLE will be with ICAO fuel reserves.