Soldato
I've no idea to be honest unless they just accelerated more slowly from Gatwick to save the engine but it's unlikely.
If he can get out of Cuba loaded on 5200 feet of runway with a lower air density then they certainly didnt need to use even 2/3rds of Gatwick.
5200 does seem very short. You have put me off that holiday destination Not much room for error there
Its ok, landed there twice now and its fine, if you do miss the end of the runway, you have mangrove swamps and alligators to stop you