FAA invites proposals to develop new unleaded aviation fuel

The US Federal Aviation Administration (FAA) has invited fuel manufacturers to submit proposals to develop a new unleaded fuel by 2018.

The FAA hopes that unleaded fuel would replace 100 octane low-lead fuel currently being used in most aircraft.

FAA Administrator Michael Huerta said: "The FAA knows the general aviation community and the Environmental Protection Agency are focused on this issue, and we look forward to collaborating with fuel producers to make an unleaded avgas available for the general aviation fleet."

The agency is advising fuel producers to submit the data packages for candidate replacement unleaded fuel formulations by 1 July for evaluation by the FAA.

By 1 September 2014, the FAA will select around ten suppliers and the formulas submitted by industry developers will be tested at the agency’s William J Hughes Technical Center using a $5.6m research and development funding granted under the President’s 2014 budget.

Over the next five years, the agency will ask fuel producers to submit 100gal of fuel for phase I testing and 10,000gal for phase II.

Following the first phase, it will select up to two fuels for phase II, for engine and aircraft testing.

The agency will accumulate standardised qualification and certification data for fuels, as well as property and performance data.

The FAA noted that it would evaluate the capability of candidate fuels based on their impact on the existing fleet, their production and distribution infrastructure, their impact on the environment and toxicology, as well as economic considerations.

To date, the FAA has tested more than 279 fuel formulations as part of its efforts to find a ‘drop-in’ solution, which would require no aircraft or engine modifications.

The latest move by the FAA is in response to the July 2012 Unleaded Avgas Transition Aviation Rulemaking Committee report which stated that a ‘drop-in’ unleaded replacement fuel is unavailable and may not be technically viable.

Therefore, an industry-government led initiative called the Piston Aviation Fuels Initiative (PAFI) will support the development and deployment of a new unleaded avgas with the least impact on the existing piston-engine aircraft fleet.

According to the FAA, there are about 167,000 aircraft in the US and a total of 230,000 worldwide that depend on 100 low lead avgas for safe operation.

The 100 low lead avgas is the sole transportation fuel in the country that comprises tetraethyl lead (TEL), a toxic substance, to generate high octane levels needed for high-performance of the aircraft engines.

Operations with inadequate octane levels could result in engine failures.

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Image: FAA noted that the new unleaded fuel would replace 100 octane low-lead fuel currently being used in the non-commercial airliners. Photo: courtesy of Suzanne T.