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G100UL in Service: Users, Issues, Insurance

G100UL is in service but a lot of misinformation is still out there, plus some users are reporting problems. Here’s what we see going on.

Rick Durden
Verified

Edited By:

Omar Filipovic

Screenshot of Beech Bonanza skin panel soak test in G100UL fuel, left; 100LL fuel, center; and 100LL fuel with 14 percent extra aromatic tolulene added for a total of 25 percent tolulene, right. Time lapse photography at top. At the time we prepared this article, the panels had been soaking some two weeks with no paint degradation. The test is expected to go on at least another week. Information about the test is on the GAMI website.

Last month we started our two-part piece on the FAA-approved, high-octane unleaded avgas, G100UL, now that it is being sold commercially. We reviewed early comments from users, addressed a concern from an avgas vendor and went through the quality control procedures under avgas that is FAA-approved for aircraft engine use via the ASTM/FAA approval route and the FAA STC route.

We pointed out that the production testing of G100UL avgas as approved by FAA STC is more rigorous than that of avgas approved by the ASTM/FAA route. ASTM avgas is tested by its producer who creates a Certificate of Analysis and then ships the avgas if it meets spec—the producer self-certifies its own avgas.

Rick Durden

Senior Editor Rick Durden has written for Aviation Consumer since 1994 and specializes in aviation law. Rick is an active CFII and holds an ATP with type ratings in the Douglas DC-3 and Cessna Citation. He is the author of The Thinking Pilot’s Flight Manual or, How to Survive Flying Little Airplanes and Have a Ball Doing It, Vols. 1 & 2.