LSA Aircraft

[checkride]

Hi Guys

i want to do hour building for Comm license, so looking for a LSA aircraft. What would be the best or cheapest option I am a Newbie to LSA . Main thing is that it needs to run on avgas.

[Stephan van Tonder]

Why on earth would you specifically look for something that will cost you MORE to run?. But with that requirement you must look at Jabiru they recommend Avgas where rotax 912 series engines are recommended to run on 95 oct mogas. Right currently avgas is almost R4/l more expensive. So at the moment every hour you fly will cost you almost R50 an hour more in avgas in those class airplanes. Also you don't give much detail - are you buying or wanting to hire and fly. Not many companies hire & fly LSA planes and just about the only option might be Jabiru again. Which area are you in?

[checkride]

the reason i specified avgas is because 90% of all airports use avgas, so to me it would be the most logic point. Plus where
i want to fly there are airports with no mogas and anyway to get mogas you have to go to a petrol station which is not convenient for
me. Running avgas on a LSA aircraft is still far cheaper then buying a Cherokee or a Cessna. Sorry if i sound like i am being cocky.

[Stephan van Tonder]

I understand that airports have avgas. That leaves your choices really to anything that doesn't have a rotax 912 as I said before. You still didn't say where you are and if you are buying or hiring to fly as that will guide poeple's response to help you.
There are guys at Rhino airfield that H&F a jabiru with block time allocations at non-peak hours at a good price.

[checkride]

I will be looking at buying an aircraft

[Mogas]

Just to clarify.
Rotax 4 stroke only recommends unleaded so that you can maintain the 100 hour oil change interval.
Should you choose to run your motor on avgas the oil change interval comes down to 50 hours, this is because some of the lead in the avgas ends up in the oil and reduces its optimum performance after more than 50 hours.

[checkride]

so what you say is that a rotax engine can run on avgas but i will need a oil change every 50 hours still cheap then buy and maintain a Cessna and Cherokee.

[Flooi]

By far the cheapest Avgas LSA is Jabiru. 10-12lph for the 2200 and 18-22lph
for the 3300. Maintenance is also inexpensive. They are real long distance crunchers
and easy fliers.

[Stephan van Tonder]

http://www.conairsports.co.uk/912%20mai ... %20bal.pdf
http://www.rtx-av-engines.ca/PDF/techinfofuel.pdf

[johnsa]

Just to clarify.
Rotax 4 stroke only recommends unleaded so that you can maintain the 100 hour oil change interval.
Should you choose to run your motor on avgas the oil change interval comes down to 50 hours, this is because some of the lead in the avgas ends up in the oil and reduces its optimum performance after more than 50 hours.

Is it fair to conclude that a 80 bhp rotax can run on mo and avgas? I get that of Stephan his pdf what I don't understand is why you have to change the sparkplugs?

[Stephan van Tonder]

Spark plugs actually foul up easier because of leaded fuel - the lead leaves that white deposit that people so liked in car exhaust pipes. That's the same reason why cars normally had plugs changed at the 15000 km service. When you use unleaded you can actually change your car's sparkplugs at 60000km specially if you use the thin electrode platinum plugs. Leaded isn't a nice clean burning fuel and really the only reason it existed was that it was an easy(cheap) way of upping octane and lubricating the valve seat. With using the correct valve seat material and having correct octane there is no good reason for having leaded fuel. Leaded fuel also affects other sensors like Lambda probes(not common on aircraft) and EGT probes and they last much better when you are using unleaded.
Keep watching - in a couple of years from now leaded fuel will disappear even in aviation.

[johnsa]

I always thought there was an other reason as well when you have an engine without catalysator it can run on both but with lead in the mogas it turns out more power.....

[Stephan van Tonder]

That is another old-wifes's tale john. The thinking was that becuase you have to retard the timing slightly it now makes less power. Well not quite true. Let me tell you something from my experience.
I used to race and prepare VW challenge cars - so basically 4 cylinder 1800 8 valve injection engines. There are 3 classes and the class B engines had the following spec - 10.5:1 compression - 286 degree cam - not gasflowed head 1823 cc max.
Due to the comression ratio we had trouble with 93 leaded so we used to run them om 102.6 leaded racing fuel and that was also the standard fuel available. Then came the time of going to unleaded and suddenly racing fuel became scarce and very expensive. I for one was very unhappy and blew the leaded is better trumpet as loudly as anybody else. Then there were promises of 98 unleaded racing fuel but it just wasn't forthcoming. So we decided to try 95 unleaded. Stuck it on the dyno and with fixing the tuning it made exactly the same power as 102.6 octane and at a heck of a huge cost saving as the guys were getting charged R280 for 20l of racing fuel.
There is nothing wrong with the 95 unleaded in SA and I run a couple of serious performance cars on it - including a 2l 16v golf with a huge turbo on it. I have totally changed my mind and I'm quite happy to recommend the 95 unleaded fuel to anybody that has an engine that is capable of running it. There are a lot of bigger aircraft engines now classified to run unleaded mogas.

[johnsa]

Thanks for the answer Stephan