Weight & Balance C of G
As one who spent some 8 years on loadsheets, some of the posts above reminded me of one fairly regular airline that diverted to Luton that always insisted on the aircraft being trimmed right on the aft limit. The aircraft was a B707 and as I thought it was an unusual request, I asked a couple of the Captains why. The simple answer was "it's easier to fly." I never did find out what the actual technical reason was, but accepted the answer and their aircraft were always trimmed to the aft limit when possible.