FAA webinar on use of auto gas in Rotax engines and vapor lock
- Thread starter Abid
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Mayfield
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Abid,
Thanks. I signed up for the webinar. I can't use E10 mogas in my Gobosh because the fuel tank is incompatible. I have been using premium E10 mogas in my TAG. Based on your experience, is using mogas in my 912 ULS problematic?
Jim
Thanks. I signed up for the webinar. I can't use E10 mogas in my Gobosh because the fuel tank is incompatible. I have been using premium E10 mogas in my TAG. Based on your experience, is using mogas in my 912 ULS problematic?
Jim
okikuma
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Thank you Abid. This fits in exactly with my other post on a different thread.
Wayne
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A BIG factor in the NEW-GEN gyros is correct nose wheel geometry ..... and how "dart-proof " they prove to be in a sloppy touch-down (WITH forwards roll) and an off-center cocked nose wheel! (as in rudder inputs with crosswind). The Magni have nice rearward caster , The TAG and AR1 also have a...
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If your density altitudes in summer get above 6000 feet I would avoid it.
If you have time, grab a coffee and watch these. Unfortunately my customers have had issues with terrible consequences due to gas quality. And I mean fatal consequences. I never use car gas unless I am staying right around the airport and practice area anymore.
Smack
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Jim, I used 91 octane pump gas in my Rotax 912 in a Kitfox for 15+ years with zero issues.
I flew it from Texas to Oshkosh multiple times (sometimes having to put 100LL in due to Mogas easy availibility issues.
Texas to Florida once, too.
Density altitude at my home airport gets close to 4000 ft in the summer and it gets plenty hot. Zero fuel problems.
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My experience with using automotive fuel; yours may be different.
I have found it very much has to do with conditions, the particular formulation of the automotive fuel and the aircraft being flown.
For a week I was giving flight instruction in two Cavalons by Autogiro in Utah both powered by a Rotax 914.
It had been snowing and suddenly changed with temperatures in the high nineties.
I had four engine outs from what we suspect was vapor lock in a week, two in each aircraft with one resulting in an off field landing from 7,500 feet MSL with a density altitude of 12,000.
All were after a reduction in power; the engine would stop and not restart for about 45 minutes.
I began using 100LL and had no further engine problems in Utah.
Training in a different 914 powered Cavalon in California with E10 in early spring; after idling for an extended time at Santa Inez (IZA) waiting for traffic to takeoff I aborted the takeoff because of a rough running engine. The temperature was 98 F and density altitude was around 4,000 feet although field elevation is 674 feet.
We could not find anything wrong with the engine, we added some 100LL and after dropping off my learner I flew back to Santa Maria (SMX) without incident.
We investigated further and found nothing wrong with the aircraft.
I suspect the E10 premium automotive fuel but I don’t know for certain.
I have found it very much has to do with conditions, the particular formulation of the automotive fuel and the aircraft being flown.
For a week I was giving flight instruction in two Cavalons by Autogiro in Utah both powered by a Rotax 914.
It had been snowing and suddenly changed with temperatures in the high nineties.
I had four engine outs from what we suspect was vapor lock in a week, two in each aircraft with one resulting in an off field landing from 7,500 feet MSL with a density altitude of 12,000.
All were after a reduction in power; the engine would stop and not restart for about 45 minutes.
I began using 100LL and had no further engine problems in Utah.
Training in a different 914 powered Cavalon in California with E10 in early spring; after idling for an extended time at Santa Inez (IZA) waiting for traffic to takeoff I aborted the takeoff because of a rough running engine. The temperature was 98 F and density altitude was around 4,000 feet although field elevation is 674 feet.
We could not find anything wrong with the engine, we added some 100LL and after dropping off my learner I flew back to Santa Maria (SMX) without incident.
We investigated further and found nothing wrong with the aircraft.
I suspect the E10 premium automotive fuel but I don’t know for certain.
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Smack
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Jim, I'll also add that I belonged to a Magni M16 Gyro club several years ago and that Rotax 912 also exclusively used pump unleaded gasoline.
It was mainly a training machine and I think it must have way over 500 hours by now. Probably closer to 1000. (update 2/3/2024: I hear the M-16 has about 2100+ hours now).
Also zero fuel problems, in Texas' summer and winter, to the best of my knowledge.
Perhaps, just like many other things, the fuel is just better in Texas.
It was mainly a training machine and I think it must have way over 500 hours by now. Probably closer to 1000. (update 2/3/2024: I hear the M-16 has about 2100+ hours now).
Also zero fuel problems, in Texas' summer and winter, to the best of my knowledge.
Perhaps, just like many other things, the fuel is just better in Texas.
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I liked the video presentation a lot, it was well organized and nicely presented.
There was very little new knowledge for me as I had researched mo gas after my off airport landing in the Cavalon.
I like having another way to present it to learners and it may become a homework assignment.
The graph of the falling fuel pressure as related to altitude was delightful and not something I had access to.
Something that was only tangentially touched on was the careless handling of mogas. Getting winter blend in summer may be problematic.
In my off airport emergency landing we knew it was winter blend and I had underestimated the risk.
We had climbed to more than 3,000 feet above the ground (7,500 MSL) to demonstrate an engine at idle vertical descent spin and when my learner (a helicopter CFI working to become a gyroplane CFI) reduced the power as I directed the engine quit and would not restart.
As I have written many times; in my opinion a successful engine out emergency landing in a gyroplane has a lot of luck involved.
There was very little new knowledge for me as I had researched mo gas after my off airport landing in the Cavalon.
I like having another way to present it to learners and it may become a homework assignment.
The graph of the falling fuel pressure as related to altitude was delightful and not something I had access to.
Something that was only tangentially touched on was the careless handling of mogas. Getting winter blend in summer may be problematic.
In my off airport emergency landing we knew it was winter blend and I had underestimated the risk.
We had climbed to more than 3,000 feet above the ground (7,500 MSL) to demonstrate an engine at idle vertical descent spin and when my learner (a helicopter CFI working to become a gyroplane CFI) reduced the power as I directed the engine quit and would not restart.
As I have written many times; in my opinion a successful engine out emergency landing in a gyroplane has a lot of luck involved.
okikuma
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The Cessna T-41 Mescaleros I use to fly had very finicky Continental fuel injected IO-360 engines. After a flight on a warm day with half tanks or less, the engine would not start for the second flight because of vapor lock. The procedure was to open the throttle about half way, mixture full lean and push the starter button. As soon as the engine would catch to start, one had to quickly pull the throttle back to idle and push in the mixture control to full rich to keep the engine running. If the fuel tanks were topped off and after the engine had run for a few minutes and then shut down. the third time to start was a non-event. It would start right up. The key was the temperature of the fuel in the fuel tanks. If the fuel temperature was near the ambient air temperature, the temperature spread between the warm fuel and the temperature that would cause the fuel to vaporize was small. Add cold fuel that was stored underground tanks, and the temperature spread was greater and the ability to vapor lock was greatly reduced.
I once had an 1989 mustang II that would suffer vapor lock on warm days with a half of a tank or less. Just as with the T-41. If I added cooler fuel that was stored in underground storage tanks at the gas station, the vapor lock would go away. I solved the problem by spraying a light coat of foam insulation on the outside bottom of the fuel tank and wrapped the bare stainless steel fuel line within the engine compartment with a layer of fiberglass insulation tape.
Wayne
I once had an 1989 mustang II that would suffer vapor lock on warm days with a half of a tank or less. Just as with the T-41. If I added cooler fuel that was stored in underground storage tanks at the gas station, the vapor lock would go away. I solved the problem by spraying a light coat of foam insulation on the outside bottom of the fuel tank and wrapped the bare stainless steel fuel line within the engine compartment with a layer of fiberglass insulation tape.
Wayne
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