Even though they've now got Lytag arrestor beds at each end, they're not supposed to be included in any runway end safety areas (RESA) which means the true landing distance available is notably less than what is published in civil terms. It was in 1996 that the Learjet coming off the end forced them to put in the beds:
http://www.skybrary.aero/index.php/File:LJ25_RE_Norholt_UK_1996.jpg[/IMG]
Add to that the number of obstacles penetrating the approach surfaces and the runway really has to be shortened in terms of declared distances for civil use.