Originally Posted by
etch5895
I've read that the wake turbulence generated by the 757 is much greater than what is normal for an aircraft its size (without winglets). I wonder if this has anything to do with the decision to steer clear of them.
The purpose of winglets is to reduce wingtip vortices/wake turbulence/induced drag, so in a way this is true. However separation for aircraft is determined on aircraft weight, not the presence of winglets. The increased fuel burn with conventional wings is more of a factor, really. 757s are decent planes, but now that there's planes like the 737-900 with near equal capacity and better fuel burn/lower maintenance costs, they're sort of looking like yesterday's planes.