Upgrade Rotax in sport cruiser?

[Michael Gallagher]

Is it possible to upgrade from a Rotax 912 to a 914 or 916 in a SportCruiser? Does this require an STC?
Bristell has several engine options for more HP. No such option when buying a SC. But is it allowed? Perhaps after MOSAIC? Is it up to the manufacturer to certify this? What if you get it certified as an experimental?

Also, what’s the best guess on timeline for MOSAIC implementation? Any scuttlebut on that or changes that may be likely from the NPRM? I’m not sure I understand what the industry members who requested the extended comment period are wanting changed

 

[DaleB]

Is it E-LSA or S-LSA?

If it's E-LSA, you can do it IF it doesn't take the performance beyond the allowable LSA envelope.

If it's S-LSA, you would need either permission from the manufacturer, OR convert it to E-LSA and you could do it yourself. Either way there's no such thing as an STC, since there's no type certificate.

The bigger problem right now is that upgrading would almost certainly take it outside of the LSA performance envelope, which - even if it were safe to do so - would turn it into an expensive lawn ornament from a regulatory standpoint. If it's LSA today and you take it outside of LSA specs, there is no path to making it legal to fly unless you can get Exp-R&D or Exhibition or something for it. The manufacturer says the gross weight is 1320# and the max cruise sped is 119 kt, so there's really no point in a bigger engine. That's why they don't offer anything bigger; it already meets the max weight and speed (OK, one knot lower) allowed for LSA.

As for MOSAIC and what that might mean... your crystal ball is as good as mine, I suspect. If MOSAIC removes the 120 kt limit for LSA, there might be a path that would allow upgrading existing LSA. Maybe. I have read most of it, but don't remember if it addressed modifying existing designs and don't want to go re-read it. The NPRM is open for comments until January, not sure what the timeline is after that, but we won't know the final rule until some unspecified future date.

And in any case, the cost and effort of hanging a different engine on it would probably make the idea of selling it and buying something else very attractive.