An article in the February issue of "Flying" magazine explores the future of General Aviation fuel, and what might replace 100 Low-Lead avgas after last year's call by the Environmental Protection Agency to possibly eliminate the 100-octane fuel currently used by a large portion of the General Aviation industry.
The article addresses the EPA proposal to reduce or eliminate airborne lead levels by removing Tetraethyl Lead (TEL) from General Aviation fuel. According to the EPA, 100LL fuel -- the high-octane leaded fuel commonly used in General Aviation and Legacy aircraft -- is possibly responsible for up to 50 percent of airborne lead levels across the U.S.
The problem with such a changeover, according to the article, is that a high octane fuel is necessary to prevent detonation in high-performance aircraft engines, and creating a suitable high octane replacement could be difficult to do cost effectively. Further, any replacement fuel must adhere to the American Society of Testing and Materials' standard D-910, which imposes numerous performance standards that must be met by any new aircraft fuel.
Other octane boosters are just as damaging -- if not more so -- to human health and the environment than the current lead standard, the article notes.
Several companies are addressing the problem by experimenting with new types of low- or no-lead fuel, and are imposing an accelerated timeline for rolling them out. The EPA seems willing to take a meandering approach to the changeover, "Flying" reports, but because of testing and certification requirements, companies like General Aviation Modifications, Inc. are pushing forward with attempts to find suitable replacements for 100LL. One alternative could potentially cost $5 or $6 per gallon.
Meanwhile, the Aircraft Owners and Pilots Association reports that the FAA has created an aviation rulemaking committee to advise and make recommendations regarding the pending transition to an unleaded fuel standard.
"Flying" covers much more about the potential changeover in fuel standards, and what companies are doing to develop replacement fuels. Unfortunately, the magazine's online archives sit behind a paywall and are not accessible without purchasing a hardcopy or subscribing to a digital version.
Meantime, some pilots are already working on their own solutions to the 100LL problem, including Alaskan pilot Randy Tyler, who's equipped his Avid Airdale with a gas-powered Subaru engine.
Contact Ben Anderson at ben(at)alaskadispatch.com