One thing that occurs to me is that pretty much every one can do the 280kts min clean speed of the heavy -400 but the -400s can't do the 250 standard speed without dragging flaps around and vastly increasing the fuel burn. My airline, a 737 operator wants us to get to econ climb speed as soon as possible after clean up for cumulative fuel (and emissions) savings. 280kts is a pretty good econ speed for the 737 and I should imagine most aircraft of that weight. Why not introduce a standard speed of 280 kts which every departing aircraft could adhere to and reduce fuel burn, flight times and emissions?
Kirk out…