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Regulatory Brief - Avgas (100LL) Alternatives

Regulatory Brief

Avgas (100LL) Alternatives

The issue

Dwindling global market demand for gasoline containing the additive tetra-ethyl lead (TEL) and increasing global environmental issues have raised concerns regarding the continued use of avgas (100LL) by general aviation (GA) aircraft.

The importance to our members

GA piston aircraft are reliant upon 100LL, a "specialty fuel" that is produced in small quantities when compared with other fuels. Optimistically speaking, 100LL will continue to be more expensive relative to other petroleum and energy products and, at worst, could be unavailable altogether. Currently, there is no single replacement for 100LL that is economical, requires only minor or no aircraft modification or recertification, and does not offer a penalty in aircraft performance.

AOPA's position

AOPA is interested in the ongoing efforts by a number of different groups on possible replacements of 100LL. AOPA maintains that a high-octane unleaded avgas or other product that can satisfy the needs of the entire existing GA piston engine fleet with little or no modification and at an economic price per gallon should be developed, tested, and approved in a timely manner.


  • AOPA is participating as a full member of both the Coordinating Research Council (CRC) and the American Society of Testing and Materials (ASTM).
  • Research and development is continuing under the auspices of the CRC where matrices of test blends of potential aviation unleaded fuels are being examined.
  • ASTM recently re-approved the 91/98 unleaded avgas specification. It should be noted that 91/98 could serve as a replacement for about 30 percent of the total 100LL currently consumed in the United States - contingent upon FAA certification of the fleet and a willingness by the fuel producers to produce a fuel that only addresses about 30 percent of the total avgas marketplace.
  • Through the congressional appropriations process, AOPA has been securing funding each year for the FAA's testing of alternate aviation fuel candidates at the FAA Technical Center.
  • Because the development and certification process is still likely to take years, AOPA is also working with the Environmental Protection Agency and the FAA to hold off any new regulatory requirements that would require the discontinued use of leaded aviation gasoline until such time as an acceptable and technically feasible alternative is developed.

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Updated Wednesday, August 09, 2006 8:55:29 AM