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Rotax 915 build in 9A??

Phantom30

Well Known Member
Has anyone considered building a 9A using a Rotax 915 engine? With turbo, I was wondering what the ceiling would be....and cruise at 24k.

Love my finished -12, but the building bug is starting to stir in me again😜
 
Go for it. But research lateral stability/spin recovery with the extended nose, and VNE issues (related to true airspeed; not indicated).

Oh, and whether you enjoy flying with an O2 mask all the time, and are comfortable with the additional risks of flying light a/c at those levels.

Of course, it might be a fun a/c even below the nosebleed levels.

The non-starter for me would be the cost/benefit analysis on that engine.
 
Personally I think the 915 would be the single best engine for a -9 IF the W&B could be made to work. AIUI, it is ~50lbs lighter than an O-235, and you could probably make some of that up with a CS prop.

It is also likely to be hediously expensive. I don't think you will see it retail for less than $35,000USD. Considering my O-340 cost $25K new the $$ mightn't work out unless you take a long-term view of potential fuel savings over the engine life.

Rotax parts are also quite expensive compared to lycoming and would need to be factored in too.
 
Rotax hasn't released the 915 yet. Most folks are expecting it to cost more than $30k given that the 914 sells for around $28k.
 
AAnnndd the price is out!

$35,000 USD, currently sourced from California Power Systems.

Now, that is $10,000 more than what I paid for a brand-new OX-340S from ECI, but if you were building a high-altitude cruiser that can run Mogas, it would actually pay for itself in 826 hours, based on a 50c/L saving and the same 24.2LPH fuel burn of my -9. In reality, it would probably be sooner due to the lower fuel burn of the -915.
 
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