Hi all,
I am planning a trip through Africa and the Middle-East in a Piper Archer 3. There is a MOGAS kit installed on the aircraft, so I could fly on AVGAS or auto-fuel (euro98). I already talked to Robert about his trip and he flew it on AVGAS with quite a long range. Even though I am making use of a TurtlePac extra fuel-tank, I won’t make it all the way on AVGAS.
Now, I have been suggested to take regular autogas fuel, even though this is only 88-92 octane, then use an octane booster add-on to add another 5-6 octane.
My question is about the ethanol / alcohol levels/percentages in the fuel. This would have a negative effect on possible vapour locks as well as on the seals.
What would you guys suggest (no guarantees asked) to do? How much harm would it do if I would fly 2 or 3 legs on autogas like this, then the rest on AVGAS?
Sjoerd
I wouldn’t worry about octane at all on an O-360. I would’t even use octane-booster – one never knows what it might do with your engine. If you like, you can always keep straight Avgas in one tank for take-offs and climbs.
But yes, ethanol could be a problem. On the other hand, I am not sure these countries have gotten in the habit of mixing ethanol into their fuels. What might be more of a problem could be water and dirt in the fuel. Be very careful with that.
It all depends on what kind of autogas you’ll get.
Care to tell us your rough routing?
From own – automotive – experience, I can confirm that Ethanol can seriously damage your hoses and seals. That said, you will probably only use it on a couple of occasions and re-fuel with Avgas asap. I would therefore not worry too much about it. I’ve also heard (no personal experience with this method), that in situations like this it is a good idea to mix the fuels. As boscomantico says, I would be more worried about dirt and water in the fuel – where will it come from? The nearest gas station? What’s your routing and range with the Turtlepack?
Is ethanol really an issue? I doubt! There are aviation engines certified for 15% ethanol.
But what is the real issue is methanol as octane booster.
When I started to operate my Europa in Ukraine some 6 years ago, I used 98 mogas (better according to ROTAX for a 914 turbo). About 10 hours later, the engine (140 hours back then) began to run rougher and rougher. Also, I saw that the map filter coming from the airbox began to become black instead of orange!
I discussed the issue with some local people and understood that nobody was using 98 and everybody just 95 from a specific brand. I also had to change the membranes of the carbs as these were getting like old mushrooms! All that was due to methanol in the fuel I was using.
The advice to filter the fuel is a sound one. On top of that, I would suggest to check with the local flight club or experienced local fliers what brand and fuel type they are using. And it is not always the well known brands that are the safest ones to use!
That is very interesting, ploucandco.
10 years ago, when i flew to Crimea (SR20 at the time), I had to blend the remaining 100LL with autofuel and when given the choice between 95 and 98 octance, I didn’t hesitate and chose the 98 octance fuel. Didn’t cross my mind that it might contain some “unhealthy” octance boosters…
The rough routing is as follows:
Outbound from Holland as straight as possible to Spain – Gibraltar – Marocco – Canary Islands – Western Sahava – Mauretania (both overflight only if possible) – Mali (Possibly AVGAS available) – Burkina Faso – Togo (possibly AVGAS available there) – Sao Tome island – Congo – Angolo – Namibia – South Africa.
Inbound route goes direction Kenia – then Ethiopia – Djibouti – Yemen (overflight) and Saudi Arabia – then Egype – Israel or Jordan – Israel and further on to Cypres.
I am getting help in the landing and overland clearances from Mike from White Rose Aviation (thanks to the tip of Robert) and from another company that can supply AVGAS in barrels where I might need it. However, the AVGAS price can be very expensive depending on location needed, so would like to stick to MOGAS/autofuel where needed.
There are no aeroclubs in between Dakar and Namibia, so this is the hard part. Some places we cannot go. Others, we can get permission (even for Mali) to land. Overflight is possible and allowed as long as on the airway routes. Insurance wise I covered the whole route including the use of the TurtlePac and even for landing in South-Sudan (not planning to go to it of course) and no war/fighting/shooting clause for excluding these places.
The TurtlePac is only 21 USG, so I have about 48 + 21 US$ useful fuel. I could have bought a bigger one, but I also have to take care of the W&B more of less.
There is also no AVGAS above Kenia. Only in Egypt or Jordania. I have a fuel tester to test for water/ethanol. How to filter for dirt?
I sold my old Commander 520 to Russia. Siberia, In fact. Those guys have bough a number of older airframes with one thing in common: geared engines. Turns out there’s no Avgas in Russia, and almost all the geared GO-435 (in my case), GO-480’s and GO-300’s are certified for around 80 octane Mogas. Mine was certified for 81. One of the benefits of gearing is that you don’t need very high compression to produce power, hence no need for high octane.
Mogas with ethanol is still a problem for these engines as they eat rubber and membranes. So, I think you’ll be better off with an injected engine if you have to. There’s also the case of vapour lock in hot temps as this fuel has a different boiling temp. So if you have booster pumps, use them in climb at least. Also, maybe wrap some insulation around the visible fuel lines to keep them from getting too hot.
If you install teflon fuel hoses (in place of any rubber ones) and replace all seals (o-rings in all cases I think) with ones in an alcohol compatible material, what else is left?
There are some seals in/under the engine driven fuel pump. Plus in the carb / fuel servo. But most of the fuel system should be metal.
Is the PR1422 fuel tank sealant alcohol compatible? The data sheet suggests it is fine.
