Sierra performance with Rotax 912S?

rgmwa

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#1
The published 130kt cruising speed for the Sierra with a 125hp Jab 3300 is impressive.

Anybody know how fast it goes with a 100hp Rotax? Or 80hp Rotax/Jab for that matter. Also curious to know what the fuel tank capacity is. Couldn't find that on the website.

rgmwa
 

pylon500

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#3
A 912s powered Sierra was built and sent to New Zealand, no idea what happened after that.
The instal was a bit more complicated than the Jab, but managed to fit.
 

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Garry Morgan

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#7
rotax in sierra

There are 3 sierra aircraft fitted with rotax motors a cheetah in Auckland is flying with a 80hp 912 and i heard cruising at 115 kts. another in the south island with 100hp rotax in a sierra will fly this week. dont know about the other one.the 100hp rotax looks to perform as good as the 3.3 jab
 

jpreou

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#9
A 912s powered Sierra was built and sent to New Zealand, no idea what happened after that.
The instal was a bit more complicated than the Jab, but managed to fit.
It *might* be the one I recently have been enquiring about. Or might not, since that was a Cheetah, but aren't they basically the same?
I was told yesterday in email, the following:

"My Cheetah was fitted with a Rotax 912 and a 0-120 kt airspeed indicator. I was amazed to find that it actually did 120 in the cruise at full rpm. I had to buy and fit a 0-140 kts airspeed indicator. With the wheel spats fitted it would cruise at 110 kts on 5,000rpm using less than 15lts/hr, one up and 90lts fuel. I stalled it at 35kts and it didn't seem to have any nasty tricks. With magnificent visibility through the bubble canopy and a roomy cockpit it was a fast and economical aircraft."

Might, or might not be useful info to people out there...
 

Garry Morgan

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#12
*0 hp jab 125kts full power sea lecel 110 cruise, 3.3 jab seems to varie 137-150kts depending on how the aircraft is set up . sea level 125kts cruise s/l and 137kts tas at 6k
 

jpreou

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#13
Just happened on this thread again and wondered whether there was some more Rotax experience out there by now?

There seems to be a growing anti-Jabiru sentiment here in NZ of late, and conversely a seemly equivalently strong pro-Rotax feeling, especially now that have that new 912iS version.

Finally got my microlight license and am now doing some transition training from the 'real' microlights (X-Air / Bantam B22) into a Zenith CH601 at a local club (yeah, I know, but it is available and cheap...-ish to fly).

Still have the Sierra in mind for a future build, or the Vans RV-12, which flies *beautifully*, but more expensive I think. With a family wedding in/around Sydney in 2016 I'm hoping to get to Taree and catch up with Garry and get a flight to enable me to make a decision. After that, it will be a question of how cheap I can get started! It's what I liked about the Vans RV-8 I was building; I could do it in more easily digestible chunks!

Blue skies all :-)