Can airplane performance be increased by cruising "on step"? Old timers swear aircraft performance can be increased by getting an aircraft "on step" similar to how boats are operated.




They claimed a couple extra miles per hour (airspeed was in MPH then) were common. The "step" was alleged to be a "just-right" angle of attack which 
minimized drag and allowed an airplane to cruise at a higher airspeed than normal on the same power. 

Can airplane performance be increased by cruising "on step"?
The Pilot Training Manual For The C-54 Skymaster has this to say about it: 


The manual is available at Archive.org