FAA calls on producers to come up with solutions to replace the use of harmful leaded general aviation fuel
Thu 13 June 2013 – General Aviation (GA) is one of the last forms of transportation to use leaded fuels and the US Federal Aviation Administration (FAA) is now asking the world’s fuel producers to submit proposals for developing a new unleaded fuel by 2018. According to the US Environmental Protection Agency (EPA), fuel used by piston-engined aircraft, known as avgas or 100LL (100 octane low-lead), is the largest source of airborne lead emissions in the country and exposure to the lead can result in a broad range of adverse health effects. The EPA has come under concerted pressure from environmentalists to act on the issue. However, finding a suitable drop-in replacement for 100LL avgas has so far proved elusive. The FAA has put out a request for fuel producers to submit by 1 July 2014 options for evaluation by the FAA, which will then select suppliers for laboratory and engine testing.
Around 167,000 aircraft in the United States and 230,000 worldwide rely on 100LL avgas, which is the only remaining transportation fuel in the US that contains the addition of toxic tetraethyl lead to create the very high octane levels needed for high-performance piston engines. Operations with inadequate octane can result in engine failures, says the FAA.
The EPA has found that 16 areas in the United States were in violation of airborne lead standards and that 100LL avgas was the largest source of airborne lead emissions in the country. Potential adverse health effects include damage to the central nervous system, cardiovascular function, kidneys, immune system and red blood cells. Children are particularly vulnerable and exposure can lead to IQ loss, poor academic achievement and long-term learning disabilities. The EPA has found that communities living near small and municipal airports typically used by GA aircraft – as well as airplane pilots, student trainees and passengers – are all at risk of exposure to lead emissions. It has also noted the potential harm from deposits of lead that collect on plants in agricultural areas where piston engine planes are used (see article).
The EPA has been petitioned by environmental groups including Friends of the Earth but the agency says it has no powers to regulate fuels in aircraft engines, which was the role of the FAA.
The FAA, meanwhile, says it has so far tested over 279 fuel formulations in an attempt to find a drop-in alternative to 100LL fuel but without a breakthrough. It has established the Fuels Program Office to deal with the issue and said it was working with the EPA and key stakeholders to replace 100LL fuel by 2018.
The Fuels Program Office was set up following recommendations in a report by the FAA-established Unleaded Avgas Transition Aviation Rulemaking Committee (UAT ARC), which also identified the scale of the task in finding a suitable replacement to 100LL. Its recommendations included implementing a fuel development roadmap and action plan, and the establishment of a collaborative industry-government initiative called the Piston Aviation Fuels Initiative (PAFI) to facilitate the development and deployment of an unleaded avgas with the least impact on the existing piston-engine aircraft fleet.
The General Aviation (GA) industry has said the technical challenges of removing lead from avgas are formidable and the transition to unleaded fuel would be long term. A group of GA industry interests came together in 2010 to form the General Aviation Avgas Coalition to protect its interests on the issue. The FAA and the coalition have since formed the PAFI Steering Group and are working together to implement the UAT ARC recommendations.
The FAA’s solicitation for unleaded fuel proposals will feed into the PAFI process. By 1 September 2014, the FAA says it will select up to 10 suppliers to participate in a first phase laboratory testing at the FAA’s William J Hughes Technical Center, with a further selection of up to two fuels for second phase engine and aircraft testing. Over the next five years, the FAA will ask fuel producers to submit 100 gallons of fuel for phase one testing and 10,000 gallons for phase two.
Candidate fuel testing of the multi-year programme will be funded by the government and in-kind industry contributions. The 2014 White House budget includes $5.6 million R&D funding for the Center to conduct the fuels evaluations testing.
The FAA says it will assess the viability of candidate fuels in terms of their impact on the existing fleet, their production and distribution infrastructure, their impact on the environment and toxicology, and economic considerations.
The FAA solicitation was welcomed by the General Aviation Avgas Coalition as a significant step in the search for an unloaded aviation fuel that would perform adequately in all types of aircraft.
“We understand the complexities of this search and we are confident that diligent work will help us find an acceptable fuel source for pilots, the public and the environment,” said Craig Fuller, President of the Aircraft Owners and Pilots Association, a member of the coalition.
The National Research Council of Canada (NRC) has announced a new project to assist in the development and testing of an alternative for 100LL aviation gasoline. The project will seek ways to reduce airborne pollutants released during transportation. The NRC is seeking partners and collaborators to join the research and development effort.
Following NRC's 100% biofuel civil aircraft test flight carried out October 2012, analysis revealed a 50% reduction in aerosol emissions compared to conventional jet fuel (see article). “This success is an incentive to continue to pursue our work in finding alternative jet and aviation gasoline fuels for the airlines, military, and general aviation industry,” said NRC.