Surfing aircraft vortices for energy

Extraction of energy from the trailing wakes of aircraft is discussed. The objective is to reduce the fuel burn for trailing aircraft in a formation. Past formation flight experiments showing the feasibility of the concept are reviewed. Results from a series of C-17 mission simulations are shown that provide fuel savings estimates for various mission lengths. The effects of operational constraints such as holding times for landing and formation joining, fuel reserve requirement, and spacing between origin and destination bases are also shown.