915 iS 3A - operation without prop governor

Hi David 

We released a video on this topic titled: Understanding the Different Versions of ROTAX® Engines:

https://www.rotax-owner.com/en/videos-topmenu/915-is-videos/786

Rotax installs a protective flange cover on the propeller governor pad for delivery purposes only. This cover must be removed before flight, as it is not designed for operational use. Before engine operation, the governor flange cover must be replaced with a functional governor, or the engine must be converted to a 915iS2 version.

For more information on the potential consequences of operating the engine with the flange cover installed, please review the attached NTSB investigation report. Ultimately, it is your decision whether to follow Rotax's instructions and the NTSB report findings or to rely on Sling’s notification instead.

Note: As of September 2023, Rotax began painting the governor pad cover plate RED and stamping it with "REMOVE BEFORE FLIGHT" to emphasize the seriousness of this issue.

Great question. Fellow sling builder here. I to plan to follow Rotax guidance on engine related topics. Part of the problem with Sling is when I asked them what version engine they were selling they didn’t even know. 

Sling also tells us to drill out the nut plate for the engine mount bolt next to the turbo. That nut plate is threaded for AN hardware and doesn’t need to be drilled if you use said AN hardware. Instead they provide metric bolts and nuts which is fine except that it’s a nyloc nut that is about 1/4 inch from the turbo housing. Not very good in my opinion. 

Hi Eric

Good grief! A nyloc near a turbo that runs as much as 1800 F is just insane.  We had an issue with a gyro OEM that was using them on the mounts, they will fail,  and then you have lots of problems.  

The conversion to the non-hydrolic is not that complicated.  

Cheers

Thanks all for your replies! I will adhere to the Rotax guidance on this.

For future reference I've attached the service instruction that covers the conversion from type 3 to type 2.