Think of the Green Flight Challenge flown on a much smaller course, but allowing hydrogen fuel cell powered balloons to compete against liquified natural gas powered ultralight aircraft, or solar-powered autogyros. You might get a small idea of the creativity and innovation that sponsors hope to unleash in an upcoming event.
In the town of Vichy, France, at the Vichy-Charmiel airfield, on July 9-11, the Eco Marathon ULM (Ultra Light Machines) will be held to test the limits of how little energy can be used to fly an aerial craft around a closed-circuit course three times. The rules are simple. The craft using the least energy wins – like the CAFE Foundation’s 2011 Green Flight Challenge, and inspired by the Shell Marathons for high school students who build extreme vehicles that get extreme mileage.
There are no speed or weight requirements outside those imposed by the French Civil Aircraft Authority (the DGAC) on the various types of aircraft. Since participants may include trikes, microlight aircraft, balloons, and other extremely varied vehicles, progress around the course will vary widely. Craft can be entered in one of two categories, prototypes or serial production models, and can use the following energy sources.
- Unleaded fuel
- Liquefied petroleum
- Gas to liquid
- pressurized air
- solar cells
- battery cells
- hybrid technology (combined use of combustion engine and electric motors)
Energy equivalents are measured against European Union 95 unleaded fuel and are based on the net caloric value (NCV) of the various energy sources. This should be an interesting source of possible contention in judging, although final decisions are the sole responsibility of the chief judge for the contest.
Pilots will follow a course on a 2,000 meter by 250 meter rectangle, maintaining level flight (except for the climb and descent from the course) until the end of the third circuit. Three trips around the course, overall, is 13.5 kilometers, or 8.37 miles. To check that all parameters are met, and the full course run, judges will monitor signals from the on-board GPS each craft is required to carry.
To review the multiple sub-categories to which a craft may be assigned, or to determine how different energy equivalents are determined, check out the Eco-Marathon ULM web site and the rules pages that are available as downloads.