It’s interesting to note that this article completely ignores the fact that many aircraft operate 90+ octane unleaded auto fuel. All of the Rotax four-cylinder engines use it as a recommended fuel, over 100LL aviation fuel. Many aircraft engines that were originally certified to run on 80 octane avgas can be legally operated on unleaded fuels if the owner applies for an STC (Supplemental Type Certificate.) I owned a Cessna 150 some years ago that ran better on unleaded auto fuel than it did on avgas. The oil stayed cleaner and spark plugs lasted significantly longer. Much of the use of auto fuels was pioneered by the Experimental Aircraft Association in the late 70’s and early ‘80’s. One of the other obstacles to the use of unleaded aircraft fuel in aviation engines is the fact that they still use magnetos whose design dates from the early 20th century and have fixed timing except for starting. Electronic magnetos, knock sensors, and modern computerized ignition and fuel systems could go a long way towards making unleaded auto-type fuels work in aircraft. Thanks, in large part, to many products pioneered by the EAA and Sport Aviation, the certificated aircraft engine manufacturers are slowly starting to incorporate more modern engine technology into their products. The big obstacle, as mentioned in the article, is the government, which, in this case, is the FAA. The onerous certification and testing requirements necessary to introduce new technology simply makes it economically difficult because the aviation market won’t support it. Moving to the internationally accepted ASTM standard that the Light-Sport segment of the aircraft industry is allowed to operate under would do a lot to alleviate this. However, if leaded aviation fuels were universally banned overnight, many, if not most, small, and many large, airports would close, because the private aviation segment would shut down almost overnight. That would mean no place for turboprop aircraft to land, which would shut down air carrier operations like FedEx, UPS, and even Amazon. Air Ambulances would lose their base of operations. The list goes on and on. Most communities have no idea how dependent they are on commercial and private aviation. Criticize the General Aviation Manufacturers Association if you will, but they see the handwriting on the wall, and I believe they will innovate if allowed too. Waiting for the government to act on and solve this problem is a guaranteed recipe for failure that will rely on the tried-and-true practice of kicking unpopular and difficult problems down the road to the next administration or office-holder.
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