Ever since the dawn of fixed-wing commerical aviation in the late 1910's[1] began operations in Europe, efficiency has been the name of the game. For an airline to be successful it must not only carry passengers from A to B, it must do so with the passengers paying more than what the airline pays to carry them. While there are many costs associated with operating an aircraft, like the cost of the aircraft itself (Between $75 and $110 million for a Boeing 737[2]), crew salaries, maintenance, fees to airports and many other posts.

None of these however weigh as heavily as fuel, with a 737-300 swallowing over $5000 in fuel per hour.[3] Fuel is also a very volitile cost, which has gone up lately.[4] Higher fuel efficiency equals better range, more payload and, perhaps most importantly in todays environmentally concious world, less emissions. Therefore, even as aircraft are taking shape on the drawing board, one of the primary concerns is efficiency.[5]