915IS Overhaul Experience and Costs

Sling North America's Sling TSi has gotten to TBO on their 915 twice already. They're a Part 141 flight school so they can't operate beyond the TBO, but the rest of the Part 91 world can with no problems. Rather than overhauling them, they sent their engines back to Rotax and just bought new ones. My understanding is that Rotax wanted to inspect 915s that have reached the 1200 hr TBO with the intention of increasing the TBO to 2,000 hours if everything looks OK.

As you have probably seen, the 916iS was released with a 2,000 hour TBO right out of the gate. I'm hopeful that the 915 will see a similar bump in the TBO, but I've heard conflicting info on that. Anyway, I've heard that when it comes time that a Rotax engine needs overhaul, it's nearly the same price to buy a new one, so that's what most people do.

Go check out all of the Rotax 9-series videos on EAA.org. Lots of good stuff there. 

Hi All...interesting discussion however the answer you seek is in the FAA airworthiness ticket your aircraft has.  

If you are flying an experimental, be it amature built or ELSA, then you can do whatever you want.  it is your experiment.  You are not bound by the recommendations of the OEM or the engine supplier.  if however you are flying a Special Light Sport then you are bound by the maintenance manual supplied from your OEM.  The OEM in this case is the manufacturer who signed the 8130-15 that states to which ASTM standards he complied with at the time they made it.  If in their maintenance manual states you must follow the engine manufacturer material then you are bound by that. 

Found in: 14 CFR 91.327 - Aircraft having a special airworthiness certificate in the light-sport category: Operating Limitations. ...check this out as it clearly states within this section you have to follow what the OEM shows in the manual that came with your aircraft. 

Rotax has no inspection process or on condition approval from their side.  As such you are on your own in that respect.  Talk to your FAA rep and be sure you are clear about what type of airworthiness ticket you have with your aircraft so they can refer to the correct CFR for that.  Check your maintenance manual that came with your aircraft and what they say about maintenance times before you assume too much on TBO. 

One last note.  In general Rotax overhauls, full factory approved standards,  will be about 55 to 65% of a new engine.  This formula is inline with what you would pay for a full overhauls of say a TC 235 or similar engine, percentage wise.  

Cheers