• Skip to primary navigation
  • Skip to main content
General Aviation News

General Aviation News

Because flying is cool

  • Pictures of the Day
    • Submit Picture of the Day
  • Stories
    • News
    • Features
    • Opinion
    • Products
    • NTSB Accidents
    • ASRS Reports
  • Comments
  • Classifieds
    • Place Classified Ad
  • Events
  • Digital Archives
  • Subscribe
  • Show Search
Hide Search

UAT-ARC: No drop-in replacement for 100LL

By Kent Misegades · January 4, 2012 ·

The FAA’s Unleaded Avgas Transition Aviation Rulemaking Committee (UAT-ARC), a group made up of aviation and oil industry representatives that is searching for an unleaded replacement for 100LL, met again this past December. Thanks to Lee Buechler of the Clean 100 Octane Coalition, minutes from this meeting are now available online. Two excerpts from these minutes are especially interesting:

There is confusion over the term “drop-in” fuel. It means one thing to the ARC, and another to pilots. The ARC definition means nothing changes in the production and distribution chains, as well as in the operating environment. Nothing. Pilots think of “drop-in” in purely an operating sense, without consideration for other matters. From the ARC point of view there will not be a “drop-in” fuel. From the pilot’s point of view there may be – for some, perhaps most, aircraft.

As GAfuels readers know, autogas, with nearly the same specific density as 100LL (weight/gallon), represents a true drop-in replacement for avgas that is capable of powering 70%-80% of the entire piston-engine aircraft fleet with little more than a paper STC in most instances.

The minutes also mentioned an ongoing lawsuit from the CEH against the producers, distributors and sellers of 100LL in the state of California:

As a side matter, those in attendance discussed the Center for Environmental Health litigation against avgas distributors in California. It was agreed that this matter probably represents a larger, and more immediate threat, to general aviation than anything else currently at play and that far too little information has been shared from AOPA, EAA and others.

Lead-free, ethanol-free autogas represents the only affordable, FAA-approved alternative to 100LL that is available today. Thanks to the efforts of the Aviation Fuel Club, it is making a comeback at airports, even in the state of California, home to the CEH.

The GAfuels Blog is written by two private pilots concerned about the future availability of fuels for piston-engine aircraft: Dean Billing, Sisters, Ore., an expert on autogas and ethanol, and Kent Misegades, Cary, N.C., an aerospace engineer, aviation sales rep for U-Fuel, and president of EAA1114.

Share this story

  • Share on Twitter Share on Twitter
  • Share on Facebook Share on Facebook
  • Share on LinkedIn Share on LinkedIn
  • Share on Reddit Share on Reddit
  • Share via Email Share via Email

Join 110,000 readers each month and get the latest news and entertainment from the world of general aviation direct to your inbox, daily. Sign up here.

Curious to know what fellow pilots think on random stories on the General Aviation News website? Click on our Recent Comments page to find out. Read our Comment Policy here.

© 2025 Flyer Media, Inc. All rights reserved. Privacy Policy.

  • About
  • Advertise
  • Comment Policy
  • Contact Us
  • Privacy Policy
  • Writer’s Guidelines
  • Photographer’s Guidelines