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  #21  
Old 11-05-2018, 09:58 AM
waterboy2110 waterboy2110 is offline
 
Join Date: Jul 2010
Location: SF Bay Area
Posts: 244
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Quote:
Originally Posted by DHeal View Post
See: https://legacy.rotaxowner.com/si_tb_...912-016-r1.pdf

That is ROTAX's Service Letter SL-912-016R1.

Section 3.1.3 pertains to MP and appropriate operating limits.
I've used the Vans prop pitch tool on every ground adjustable prop I set - no matter what the manufacturer or blade configuration along with a small digital level. Since I don't keep the battery in the level it gets calibrated each time I use it. I consistently see 0.1 degree or less between blades.

See thread meltdown for the gory details of not paying attention to the parameters set forth by Rotax. You can't comment on the thread since the Vans employees closed it - too much heat I guess.

The Vans posters on this forum would have you believe that something other than the parameters outlined in SL912-016 were in play here but that's simply not the case. It failed exactly as Rotax said it would given the parameters in that service letter.

In my situation every parameter in that SL was in play for an inflight engine failure.

I run about 1 degree less bite from the "recommended" pitch in the prop now and it sees just over 5200 on roll out so I feel good about that. Still see numbers in the yellow for airspeed and the bird is so light that any turbulence really pushes it around so I'm good.

It is the owner / operators responsibility to ensure that the engine operates within the parameters of the engine manufactures specification. Ignoring Rotax' "recommendations" could be costly.

And don't get me started on what it takes to work with Rotax. It took 9 months to reimburse me the $4200 for the pushrod debacle on the new engine.
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PP - ASEL
Instrument Rating
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RV12 Flying.
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  #22  
Old 11-05-2018, 10:01 AM
waterboy2110 waterboy2110 is offline
 
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Location: SF Bay Area
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Quote:
Originally Posted by AirHound View Post
Scott,
Iím fairly confident I have her set at 71.4 w/i .1.

Say, is it possible at 71.4 to get a high MP alert on climb out and it goes away at initial cruise?

Thanks,
Doug
Yes - you can configure the Dynon to set a redline for MP. The MP will unwind as you gain altitude but I wasn't comfortable not being able to use full power on takeoff. I just re-pitched the prop.
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  #23  
Old 11-05-2018, 12:28 PM
AirHound AirHound is offline
 
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Location: OFallon IL now, everywhere before
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Quote:
Originally Posted by waterboy2110 View Post
Yes - you can configure the Dynon to set a redline for MP. The MP will unwind as you gain altitude but I wasn't comfortable not being able to use full power on takeoff. I just re-pitched the prop.
Hey Waterboy How much did you flatten it out roughly - .2 or ? to obtain desired results?
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  #24  
Old 11-05-2018, 12:46 PM
rvbuilder2002 rvbuilder2002 is offline
 
Join Date: Jul 2005
Location: Hubbard Oregon
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Quote:
Originally Posted by waterboy2110 View Post
You can't comment on the thread since the Vans employees closed it
That can only be done by a forum administrator. Van's employees do not have admin. rights so have have no way to close a thread.

Quote:
Originally Posted by waterboy2110 View Post
The Vans posters on this forum would have you believe that something other than the parameters outlined in SL912-016 were in play here but that's simply not the case. It failed exactly as Rotax said it would given the parameters in that service letter.
As has been mentioned numerous times here in this forum, the cause of the failure has never been full investigated because a partially disassembled engine (with critical p[arts missing) was shipped for evaluation (who does that with a new engine that is still within it's warranty period......???), but that the USA Rotax representatives and Rotax engineers (during a meeting at the 2018 aero-expo in Germany) are confident that there was more involved to cause the failure than just the engine RPM during take-off.
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RV-6A (aka "Junkyard Special ")
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  #25  
Old 11-05-2018, 09:44 PM
waterboy2110 waterboy2110 is offline
 
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Quote:
Originally Posted by rvbuilder2002 View Post
That can only be done by a forum administrator. Van's employees do not have admin. rights so have have no way to close a thread.
Vic is both an employee of Vans and an admin on this site. I'm sure you are aware of that.

Quote:

As has been mentioned numerous times here in this forum, the cause of the failure has never been full investigated because a partially disassembled engine (with critical p[arts missing) was shipped for evaluation (who does that with a new engine that is still within it's warranty period......???), but that the USA Rotax representatives and Rotax engineers (during a meeting at the 2018 aero-expo in Germany) are confident that there was more involved to cause the failure than just the engine RPM during take-off.
Just to be clear: No one from Vans or Rotax has ever contacted me in any official capacity WRT the inflight engine failure. Only the FAA reached out after the incident.

The engines intakes were removed exactly as described in the KAI - during the timeframe of the build - to recover the drip trays and cooling plenum for use on the new engine.

Who does that? Literally all 600 912ULS builders. Since I'm both an A&P and certified Rotax iRMT I actually am qualified to dissemble and inspect these engines. I've had this very conversation with Rotax.

There's no question that the "recommended" pitch is in direct contradiction of Rotax' recommendations and the failures they have seen in the field per the service letter. That service letter IS Rotax' official stance on engine operating parameters. All other conversation, opinions and experiences cannot superceed the official documentation from Rotax.
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Last edited by waterboy2110 : 11-05-2018 at 10:00 PM.
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  #26  
Old 11-06-2018, 12:52 PM
AirHound AirHound is offline
 
Join Date: Oct 2006
Location: OFallon IL now, everywhere before
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Default Reading the Chart

Quote:
Originally Posted by DHeal View Post
See: https://legacy.rotaxowner.com/si_tb_...912-016-r1.pdf

That is ROTAX's Service Letter SL-912-016R1.

Section 3.1.3 pertains to MP and appropriate operating limits.
I need to check the limits my SV SW version has programmed MAP at. However, IF I interpret the chart correctly, then 29" at 5200RPM is the limit I can operate to?? OR is this chart more useful for inflight adjustable systems....? Like a certified C/S prop??
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  #27  
Old 11-11-2018, 09:19 PM
AirHound AirHound is offline
 
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Location: OFallon IL now, everywhere before
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Quote:
Originally Posted by AirHound View Post
I need to check the limits my SV SW version has programmed MAP at. However, IF I interpret the chart correctly, then 29" at 5200RPM is the limit I can operate to?? OR is this chart more useful for inflight adjustable systems....? Like a certified C/S prop??
No answer, or no idea...Doesnt matter, I pitched to average 5650 WOT at 3000 MSL and numbers seem real good/optimized. I feel WOT over that and the performance numbers donít improve but may decline. Just my humble opinion.
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  #28  
Old 11-12-2018, 12:00 AM
Driftdown Driftdown is offline
 
Join Date: Jan 2011
Location: Clearwater, Florida
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Quote:
Originally Posted by AirHound View Post
. . . I pitched to average 5650 WOT at 3000 MSL and numbers seem real good/optimized. I feel WOT over that and the performance numbers donít improve but may decline.
Bingo!
Thatís what we call ďthe sweet spot.Ē
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