A lot has been written about who is developing 100 unleaded avgas fuels, but we should look at who is NOT working on a candidate fuel.
Aviation Fuel
Unleaded fuels and exhaust valve recession
What needs to happen to move forward towards an unleaded future for general aviation?
Interactive map added to AirVenture FBO special deals page
FBOs across the U.S. have already started posting offers on the Oshkosh Specials page, including discounts of up to $1 per gallon on avgas, complimentary meals, picnics, and camping options.
Drop-in unleaded replacement for 100LL expected to be approved in late 2025
A fleet wide approval for an unleaded fuel for general aviation is expected in the third quarter of 2025.
More than 1 million gallons of G100 UL unleaded fuel now available
The famous Howard DGA-6 replica “Mister Mulligan” became the first airplane to fly in an air show powered by G100UL unleaded avgas.
Work continues to identify cause of valve seat recession in planes using unleaded fuel
Analysis indicates that aromatic concentration tolerances for UL94 may contribute to valve seat recession in certain flight profiles, Lycoming officials said, noting that the problem — right now — seems to be isolated to the UND fleet.
Avgas from the Wright brothers to today
There is still a lot of confusion about the transition to a new unleaded avgas, especially around the differences between fuels approved through the Supplemental Type Certificate (STC) and a specification from the American Society for Testing and Materials (ASTM). It may help to look at the history of specifications for avgas.
Aromatics may be cause of valve seat recession after using unleaded fuel
Testing by Lycoming Engines has “demonstrated that, under certain conditions, use of UL94 may impact valve seat recession.”
Murphy’s Law and the search for an unleaded fuel for general aviation
Murphy’s Law states that anything that can go wrong will go wrong. In the transition to unleaded fuel for general aviation, what could possibly go wrong?