It looks like the time has finally come to get the lead out. General Aviation Modifications, Inc. (better known by the acronym “GAMI”) has announced that the FAA has approved STCs authorizing use of its G100ULtm unleaded high-octane avgas. 

The STC covers an initial approved list of aircraft and engines specific to this STC, and it’s a big list, with hundreds of approvals. As time and experience with the new fuel moves forward, the AML (Approved Model List) for the STC will be expanded to other aircraft and their related engines, which effectively should provide certification, claims GAMI, for most of the ignition piston powered aircraft in the general aviation fleet. 

In collaborating with the FAA, said GAMI, in addition to the routine tests that are currently in process, two additional tests should provide the necessary data to greatly expand the scope of the original Approved Model List. With the successful completion of these tests, look for G100UL avgas to be a direct replacement for 100LL fuel. 

However, having this new unleaded fuel approved is just part of the no-lead equation. Distribution of the fuel will be critical to bring this to fruition. GAMI is working together with Avfuel Corporation, a global supplier of aviation fuel and services. These two entities will work in tandem to ensure that the G100UL fuel is available with the distribution chain moving the fuel from production to pump. 

Looking past this initial stage, with an expanded AML and readily available G100UL at the pump, GAMI expects existing 100LL fuel to vanish from the market, though how long that takes is anybody’s guess. There are big hurdles to overcome, including those mentioned, such as  getting STCs for the remainder of the fleet and expanding the distribution chain beyond a single partnership.