Pom Pax,
I'm no expert on the Airlift, but I'd think that they would have to land at one of the "feeder" airfields for the last leg (Celle, Faßberg,Wunsdorf ?) to refuel.
Otherwise they'd have to refuel at Gatow for the return trip, and we were supposed to be flying fuel into Berlin !
I have read that the RAF's speciality was hauling coal in Yorks (don't know if it was true). Many people here have airlift memories.
Danny.