One of the questions I wanted answered at this year’s AirVenture in Oshkosh was “what is the latest on unleaded avgas?” To find out, I did numerous interviews and attended several seminars. The big news was the immediate introduction of a 94 motor octane unleaded avgas by Swift Fuels. The fuel will be marketed with […]
Visser's Voice
Will diesel engines power general aviation?
In my last column, Tracking down answers at Oshkosh, I wrote about the disappearance of the diesel cycle engine in the Cessna 182. From that article, people might think that diesel cycle engines in general aviation aircraft are dead. Well, maybe not dead, just on life support. The reason for the continued interest is more from third […]
Tracking down answers at Oshkosh
Over the years, you may have noticed my lack of enthusiasm for many of the changes and upgrades made to the Experimental Aircraft Association‘s (EAA) Oshkosh event, now called AirVenture. In the good old days, Oshkosh was a technical information exchange and social gathering. The primary purpose of the event was for homebuilders and aircraft owners to […]
Can I use #1 diesel in my airplane?
I have received numerous questions from farm and ranch pilots about using #1 diesel fuel in aircraft with diesel cycle piston engines. The reasoning behind these questions concerns the availability and price of Jet A in rural agricultural areas. #1 diesel is cheaper and more readily available. On the surface — and in theory — the answer […]
Why does GA get no respect?
Regular readers will remember that my last few columns have been on concerns with the proposed new unleaded avgas. Well I am done venting on that subject for now, so I am getting off that bully pulpit until the alphabet groups and the federal agencies produce some more column fodder. And I am getting on my soap […]
Why worry about knock in an aircraft engine?
My last several columns have been on the relationship between knock and unleaded fuels in aircraft engines. I have received several questions from people who have experienced knock in their car engines, especially in the 1970s and 1980s. They note that knock didn’t harm their auto engines, so why am I worried about a little knock […]
The devil is in the details with unleaded avgas
In the 1970s, the automotive world switched from leaded to unleaded fuels and the oil companies did a lot of research on knocking and how to prevent it. One of the big projects involved octane requirement increase (ORI). In this program, cars were rated for octane requirement when new and then every 2,000 miles. The octane […]
Testing the octane rating of aviation fuel
A wise man once said, “If you can keep your head when all about you are losing theirs, then you have evidently not grasped the gravity of the situation.” When I first started working at Shell back in the late 1960s, we did a lot of work on octane requirements. Due to the poor correlation […]
The difference between 100LL and 100/130LL
In my last column, I proposed a way to get the lead out of 100LL — or at least out of the name. I received a number of responses, both pro and con. I always appreciate both types of comments and try to learn from them. I would like to address just one of the negative […]