The concept is simple; we weigh your aircraft and contents, fly a 400 or 200 mile course, record the time it takes to complete the course then weigh your aircraft and contents at the completion of the flight.  The difference between the before and after flight weights indicate the amount of fuel burned.  The fuel usage divided into the miles flown, gives miles per gallon (MPG).  However, for a more sophisticated evaluation of your aircraft, we also use a formula created by the Comparative Aircraft Flight Efficiency Foundation (CAFE). We award prizes for the competitors with the best MPG ratings as well as awards for the best CAFE scores.

Classifications: For a more equitable competition, we group aircraft by their gross take-off weight.  Heavier aircraft have a tendency to burn more fuel than lightweight aircraft yet can usually carry more passenger payload.

The weight classifications are:

500 kg or less (1102 lbs.) 

501 to 750 kg (1653 lbs)

751 to 1000 kg (2204 lbs)

Passenger payload: Which aircraft has more efficiency potential? A single seat aircraft that achieves 30 miles per gallon or an aircraft that carries four adults while flying 30 miles per gallon consumed? Of course, the aircraft that can haul the most passenger payload has the most potential as an efficient form transportation.  The CAFE formula gives credit for passenger payload in the event. A realistic representation for passenger payload is 200 pounds per seat and so, we allow up to 200 pounds of passenger weight, per seat, for calculation of the CAFE score. We allow the use of ballast to augment actual people payload to achieve the CAFE score enhancing 200 pounds per seat. Favorite forms of ballast with the competitors are plastic containers filled with water. However, removable seat cushions, headsets, maps, purses, iPods, etc. can also count as ballast.

Speed: A bicycle uses much less fuel than a Toyota Prius but the potential speed of the hybrid car is much more useable as a form of transportation.  Aviation's speed is its most attractive feature as a form of transportation for most people. The CAFE formula weights speed as a very significant element of true utility and efficiency.  We presently limit the minimum speed on the course to an average speed 120 miles an hour for the 400 mile course and 60 mph for the 200 mile course. We do this for two reasons; first, to stress the utility of speed but also to limit the time required to run the event.

The weigh-in process of the aircraft is exact and is time consuming. Wind can affect accuracy of the weighing process so calm conditions or an indoor area is needed. We weigh the aircraft and passenger ballast on the day before the competition then weigh the passengers just before departing for the flight. Upon completion of the course, the aircraft and passengers are weighed as one unit. The total weight before, versus the total weight after, is used to calculate gallons of fuel used.

Interested in competing? Click this link, or the link on the page menu, to download an Excel Spread sheet so you can calculate your potential CAFE score.