Sport Pilot Talk

MrMorden wrote:The 701/750 series has had every engine in the world hung on it, and I think that choice makes a big difference in how the airplane flies. My choice would be a Rotax 912 100hp over a heavier O-200, Jabiru, VW, etc.

Including a turbo prop! Which is a cool hack but...

rsteele wrote:

MrMorden wrote:The 701/750 series has had every engine in the world hung on it, and I think that choice makes a big difference in how the airplane flies. My choice would be a Rotax 912 100hp over a heavier O-200, Jabiru, VW, etc.

Including a turbo prop! Which is a cool hack but...

Indeed! I bet that turbine runs about ten minutes before it's out of fuel.

I have seen two-strokes on them too. WTF with that!

zaitcev wrote:Not enthused about their choice of O-200 because I'm a lardbutt pilot at 220 lbs, but as long as it permits them to keep the cost down...

I wondered this, too. I don't think the Rotax 912 is necessarily any more expensive (initial cost, fuel, maintenance, TBO, etc) than the O-200, and is certainly more efficient.

Perhaps it's a "Made in the USA" thing...

Cost of a 912 is a major factor for builders of 701. My own builder is building one right now and he selected a Revmaster VW. A 912ULS is more defensible on the CH-750 where its power is needed.

zaitcev wrote:Cost of a 912 is a major factor for builders of 701. My own builder is building one right now and he selected a Revmaster VW. A 912ULS is more defensible on the CH-750 where its power is needed.

Used 912s can be had for $7k-10k. Not dissimilar to a used O-200. And only $1k-3k less than a VW engine.

A new O-200D is $23,500 and a new 912ULS is $18,500. A new Revmaster is about $8k.

Personally, I think a VW engine is the wrong choice for a 701. A 2180cc VW makes about 76hp and weighs 161lb...the power to weight just isn't there. It will fly, but it will turn a STOL airplane into a sorta-kinda-STOL airplane. Just IMO, of course, but we have a VW-powered 701 locally and it's kind of a performance dog.

Last time I checked, a new 912ULS in the crate cost $19,000 US. Yes, that's a good chunk of change, but you'd be hard pressed to find anying else new with 100 HP and 2000 TBO any cheaper.

A 912ULS is now around $16,800. Prices for the 912 and 914 engines have come down.

Kind of cool replacing all 8 spark plugs for about the price of a single aircraft spark plug!

FastEddieB wrote:Kind of cool replacing all 8 spark plugs for about the price of a single aircraft spark plug!

Gotta love it!

I see that the O-200 being factory-installed in the CH705 SLSA is FAA certified, where a Rotax isn't.

Is that an advantage/disadvantage?

There is a certified version of the Rotax. It's the 912S. Costs maybe 10k more. One advantage is it can be IFR approved while the ULS is not.

drseti wrote:There is a certified version of the Rotax. It's the 912S. Costs maybe 10k more. One advantage is it can be IFR approved while the ULS is not.

Are you sure about that? It is my understanding that ASTM does not have a IFR standard, and until they do, no new SLSA can be IFR certified. Certified engine or not. Prior to 2010 whether the airplane could be flown IFR had to do with how the operating limitations were written, and approval or lack of prohibition from the manufacturer.

I'm in FL right now, so can't access the document in my office, but there was an FAA Legal interpretation that says, absent an ASTM consensus standard, manufacturers can exclude or include IFR in their operating limitations.

CFR 21.190 says that the airplane must meet a standard for issue of an airworthiness certificate. The only accepted standard is ASTM, and it says no flight in IMC. Are you saying the FAA has issued a letter allowing the manufacturer to not follow ASTM standards? Maybe the letter applies to aircraft built before the change in the ASTM standards that prohibited flight in IMC.

3Dreaming wrote:

drseti wrote:There is a certified version of the Rotax. It's the 912S. Costs maybe 10k more. One advantage is it can be IFR approved while the ULS is not.

Are you sure about that? It is my understanding that ASTM does not have a IFR standard, and until they do, no new SLSA can be IFR certified. Certified engine or not.

A builder of CH-750 can write proper limitations, I think.