The US Federal Aviation Administration is planning to spend $10 million over the next five years to develop an unleaded aviation gasoline to replace the 100 octane low-lead (100LL) fuels used in piston-powered aircraft.

The effort comes as the US Environmental Protection Agency prepares to issue an advance notice of proposed rulemaking to reduce lead emissions in avgas, the only remaining mobile source of lead in the USA, according the General Aviation Manufacturers Association.

Included in the FAA's 2011 budget request, which has not yet been approved by the US Congress, is $2 million in research funding that will include engine ground testing of candidate unleaded fuels at the agency's Atlantic City technical centre.

The FAA and industry partners, including GAMA, fuel companies and two universities, will also begin research into ways to modify high performance general aviation engines to run on unleaded fuels.

While many smaller engines have been cleared to burn automobile gasoline, higher-performance engines require the tetraethyl-lead additive in 100LL to prevent detonation problems that can lead to engine failure.

The FAA's ultimate goal is to develop a replacement fuel that will be transparent to the pilot, in terms of its delivery and use, with equivalent performance to 100LL.

Source: Flight International