Lycoming Working for UL 91 Avgas Approval
- They’re committed to excellence.
- They’re innovative. Very, very innovative.
- They’re committed to pioneering better, more affordable flying experiences for general aviation pilots of all skill levels.
For example, Lycoming first approved an unleaded fuel, AVGAS 91/96 UL, for more than 30 engine models in 1995. Recently, however, Lycoming began exploring new ways to make more widespread the use of UL 91 avgas – and it looks like they’ll succeed.
The company recently applied for approval in Europe to use UL 91 avgas with several of its lines of engines, including its 233-, 235-, 320- and 360-series (with some 540-series engines available shortly thereafter). According to a Lycoming spokesman, the approval process should take only weeks.
“Many of our engines have been approved to operate on unleaded aviation fuel since 1995,” says Michael Kraft, Lycoming senior vice president and general manager in a statement released by the company. “Recognizing that not every fuel is available worldwide, we are continuously working to expand our specified fuels list to give pilots the flexibility they need to operate safely in the broadest range of locations. Our approval of UL 91 supports recent actions by European fuel producers and EASA to stabilize aviation fuel supplies for light aircraft and respond to environmental concerns over lead in aviation fuel.”
Still, it might take some time to be able to use such an engine in the U.S. airspace.
[A Lycoming spokesman] told AVweb, Wednesday, “If your engine is approved on this fuel then your airframe is automatically approved … in the EU. In the U.S., if the engine is approved, you may still need approval for the airframe.” The first U.S. approvals should greet engines that were originally approved on 80/87 avgas. Those engines usually are approved for 80/87 or higher octane fuel. Some engine models may have received type certificates after 80/87 stopped being available, but should be able to run it also. Those engines will need to be “validated,” Miller said, citing the “weeks — not months” timeline.
Kraft says that UL 91 is not a replacement for 100LL (low-leaded fuel) — it’s not even available from any major distributors yet in the United States — but it is an ideal alternative for aviation needs to automotive gasoline. However, Lycoming is determined to find a long-term unleaded 100LL replacement fuel.
If you have questions about when your Lycoming engine will be approved to run on UL 91 avgas – or if you have questions about whether or not your aircraft will qualify, give us a call. Or go ahead and take a look at our complete line of tough, top-quality Lycoming engine accessories.