Your blogger is attending the AERO Friedrichshafen show in sunny southern Germany. Among the hundreds of exhibits are many new aircraft engines, some with names like Continental and Lycoming most Americans would recognize, but others that are relatively unknown in the U.S. While a full report will have to wait until next week, one thing is very clear: Europeans have already accepted a lead-free aviation future.
Lycoming gets FAA nod to update list of approved fuels
Just weeks after Lycoming Engines announced it would seek approval to operate certain engines on ASTM D7547 UL 91 unleaded avgas, it has received FAA approval to update its listing of approved fuels.
Lycoming’s newly available Service Instruction SI-1070R lists 35 engine models approved to operate on ASTM D7547 UL 91 fuel. The models are members of the 235, 290, 320, 340, 360, 435, 480 and 540 engine families. SI-1070R also specifies the lubricants to be used in conjunction with UL 91. SI-1070R is available at Lycoming.com.
Autogas expert Harry Zeisloft dies
The sad news of the death of Harry Zeisloft reached us this week. As reported by the EAA, “Harry Zeisloft, who was one of EAA’s longest-serving board members and an integral part of EAA’s effort to create the auto fuel Supplemental Type Certificate (STC), passed away Sunday, April 1, in Mesa, Arizona. He was 93.”
UL91 explained
Last month, Lycoming expanded its support for alternative fuels by announcing that it was seeking EASA approval for operation of many of its engines on the unleaded aviation fuel UL91. The company also announced it was planning to approve its new O-233 LSA engine for autogas, a clear response to engines from Rotax, Jabiru, ULPower, HKS, Hirth, AeroVee and others that have been approved for autogas for years.
ULPower’s new 6-cylinder autogas engines
Belgian aircraft engine maker ULPower recently announced a new line of FADEC-controlled, autogas-burning six-cylinder engines ranging in output from 140-200 hp.
Lycoming seeks approval on unleaded avgas
Lycoming Engines has applied for approval to use UL 91 unleaded avgas in several of its engine models, including those in the 233, 235, 320 and 360 engine families. Engines in the 540 family will follow as Lycoming completes additional validation, Lycoming officials said.
FAA avgas research funding ‘critical’
Officials at general aviation’s alphabet groups have sent a letter to Congress emphasizing that the FAA is a critical participant in continuing research to develop an unleaded aviation fuel, according to a report at AOPA.org. The letter urges Congressional support for funding in the agency’s fiscal 2013 budget.
The staggering chicken test
In response to a previous column in which I expounded on the problem of exhaust valve recession with unleaded fuels, I received a note from Ron Newberg, which reminded me of work done by the oil companies back in the early 1970s. I actually ran some of these tests, in which we demonstrated that Tri-Cresyl Phosphorous (TCP) added to an unleaded fuel reduces the amount of exhaust valve recession. It worked well. Since TCP is approved for almost all aircraft piston engines, it is an immediate approved solution for the exhaust valve recession problem. But, alas, nothing is that simple. TCP will work, but it has some health concerns.
Ever-increasing prices make fuel planning more important
The price of oil has risen nearly 20% in the last six months, to well over $100 a barrel, pushing up aviation fuel costs and forcing pilots to do redouble their focus on fuel planning, according to a report at NBAA.org, which offers several tips on how to deal with the increased costs.
The FBO fuel sales model is broken and anti-competitive
In almost every article about the future of leaded avgas, this statement appears, “… only one fuel will be stocked by the FBO system.” This particular quote comes from a reply by Mac McClellen to Todd Petersen in Mac’s latest Left Seat blog on the EAA’s website. You will also find it in almost every article and editorial from any aviation alphabet organization about the modern state of 100LL avgas.
My question is why are FBO’s the sole determinant of fuel sales on an airport? The answer is because of an obsolete view of what an FBO should do.


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