the 757 cannot be turned any quicker than 50 minutes.
All depends on how many pax, what number of bags, and the size of the crew loading it.
OK, it'll never turn as fast as a small 737, if for no other reason than it takes a bit longer to get the equipment up to the holds to get at the bags. Having said that, a fully loaded 737 800 isn't going to turn in 20 minutes either. I know, I've done them, and charter 800's are usually scheduled for about the same as the 757's, about an hour. Anything less is asking for hassles, delays, or both.
The worst combination is a charter 757 single cabin class, so about 240 seats, on a winter ski charter during the school holidays, by the time you've got all the skis, boots and the rest of the bags out, then the outbound bags in, 50 minutes is indeed tight.
A "normal" bucket and spade is not quite as bad, it can be done a bit quicker.
Summer student charters from Spain to Ireland are a nightmare, I've seen them arrive in with all holds stuffed to the gills with bags, and it then takes close on an hour to get them unloaded, let alone load them for the return leg, I think the worst count we had on one of them was 445 pieces, and anyone that thinks that little tiny students only pack little tiny bags is in for a big shock!!!
Transatlantic scheduled 757's are no fun either, Americans are very good at packing 75Lb monstrostities, and they always have more than one of them!!
Remember that people like FR who are aiming for 20 minutes are also working on a much lower bag count than charter flights.
Best I ever managed, which was with a good crew, and we worked like h
l to do it was a First Choice 757 that arrived in late, and we couldn't get a slot extension for the outbound due to late night limits at the destination. It was full both ways, (so about 300, maybe 320 bags off and on) and it was on blocks for under 40 minutes, which included fuel. What also helped was that the landing roll was long, so the brakes weren't too hot when it arrived on stand, otherwise it would have been with us for longer.
Given the ferocity with which some 737's arrive and stop, I have often wondered about the implications of a late take off abort after a 20 minute turn round, and what sort of stopping performance would really be available from the brakes. If I stop and think about it for too long, the answer is that I probably wouldn't want to know!
