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02-12-2020, 09:38 AM
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Join Date: Sep 2006
Location: Halifax, NS
Posts: 179
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Engine Failure
First of all glad you're ok. 300 feet and a turn back to land. I was always taught that is a recipe for disaster. The classic stall spin to the ground. I know I wouldn't get away with that in the 4. Is this something that is safe in the 12?
__________________
Brian Eisner
RV-4 C-GRJT
Bedford Nova Scotia
Canada
Dues paid for 2019
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02-12-2020, 09:47 AM
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been here awhile
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Join Date: Dec 2004
Location: North Alabama
Posts: 4,301
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Quote:
Originally Posted by eisnerrv4
First of all glad you're ok. 300 feet and a turn back to land. I was always taught that is a recipe for disaster. The classic stall spin to the ground. I know I wouldn't get away with that in the 4. Is this something that is safe in the 12?
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It was in this case.
Makes a big difference when the engine is still producing some power....and the -12 is a different aircraft from the -4.
Last edited by Sam Buchanan : 02-12-2020 at 09:50 AM.
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02-12-2020, 10:02 AM
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Join Date: Sep 2006
Location: Halifax, NS
Posts: 179
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Engine Failure
Ok thanks Sam.
__________________
Brian Eisner
RV-4 C-GRJT
Bedford Nova Scotia
Canada
Dues paid for 2019
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02-12-2020, 10:07 AM
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Join Date: Jan 2012
Location: Northeast Ohio
Posts: 685
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Felix,
Very early in my flight testing I had a similar incident with my 912ULS powered RV-12. In my case, at around 300 feet during a 65-70 knot climb out, the RPM's went instantly from 5,200 to 4,000 accompanied by some roughness and a small whiff of fuel. I pulled the throttle out and eased it back in and the engine started running rough again if the RPM were much above 4,500 so I kept the power around 4,000 and told the tower I had a partial loss of power. I was able to easily make it around to an intersecting runway for a safe landing.
Using Savy Analysis, I was able to determine the left carb went rich at the time of the incident accompanied with a small drop in fuel pressure and small increase in fuel flow ... because the EGT dropped on the left side. Removed the left carb ... floats checked OK, needle valve looked good, so then flushed the carb/fuel line using the electric fuel pump. Only found one tiny speck of crud ... which I'm assuming got caught under the needle valve causing the carb to go rich. Have not had the issue since.
Suggest you save the data file from your SkyView and use Savy to chart out the data ... the charts will show you if you went rich or lean based on what happens to the EGT.
Since auto fuel is being used and you are in a warm part of the country, I'll pass on what I've been doing with good results. In the spring when the temps here begin to get into the 80's if there is still only winter blended fuel available at the pumps, I mix in some 100LL (at least 30%) until the summer blend fuel is available. This seems to really lower the possibility of vapor lock issues due to the combination of winter blended auto fuel and warm temperatures.
Good job on getting the bird safely back on the ground.
Happy flying,
__________________
John
www.dogaviation.com
RV-12 Wings, Empennage, Fuselage, Finishing, Avionics and Powerplant kits all completed
Now Flying!!
Donation paid until September 2021
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02-12-2020, 10:30 AM
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Join Date: Oct 2010
Location: Crystal Lake, IL
Posts: 25
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I am not familiar with a rotex engine, however if you had an electric boost pump on, it should have over come a vapor lock.
Mike Hepperlen
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02-12-2020, 10:50 AM
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been here awhile
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Join Date: Dec 2004
Location: North Alabama
Posts: 4,301
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Quote:
Originally Posted by Mike Hepperlen
I am not familiar with a rotex engine, however if you had an electric boost pump on, it should have over come a vapor lock.
Mike Hepperlen
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You can't count on that. If fuel is boiling in the carb bowl or downstream of the pump(s), it can disrupt fuel delivery enough to reduce power or even stop the engine, even in a Lycoming. Been there...done that.....
Winter blend auto gas is fickle stuff.....I don't like it.
Last edited by Sam Buchanan : 02-12-2020 at 10:55 AM.
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02-12-2020, 11:01 AM
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Join Date: Nov 2013
Location: Prescott, AZ
Posts: 1,614
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well done
I will let your research figure out the engine problem, but the flying was superb. Nice bank angle and pitch control. I am in the camp that pilots/owners should try this out now and then to determine the altitude needed for success. I have put it to use in a Luscombe, Cessna 210 and an RV9A. In the case of the RV, I only turned 90 degrees left to use the intersecting runway end. (rain water in fuel)
Training in advance is always a good thing. Well done sir!
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"Kindness is never a bad plan."
exemption option waived. Donation appropriate.
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02-12-2020, 04:41 PM
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Join Date: Nov 2009
Location: Independence, OR
Posts: 316
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Before you do anything drastic, pull the float bowls. If you see debris then I bet that is what caused this problem.
Similar happened to me in my CTSW. A piece of debris can pick up causing a partial power loss.
__________________
John Horn (donated for 2020)
Independence, OR
LSRM-A, CFII
Rotax Service, Maintenance, and Heavy Maintenance Trained
Building an RV-12, N7878H reserved
Flying a Flight Design CTSW
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02-12-2020, 06:24 PM
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Join Date: Aug 2018
Location: SC
Posts: 11
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The (im)possible turn
Congrats and well done on getting it safely back on the ground. Here?s a link to a webinar of Brian Schiff talking about ?The Possible Turn? on the NAFI website. At some point after takeoff, it becomes possible to make it back to the airfield. He describes how to figure out that point and how to practice. He also describes when not to turn back. Cheers.
https://www.mentorlive.site/program/20.html
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02-12-2020, 11:28 PM
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Join Date: Nov 2012
Location: santa rosa
Posts: 68
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210/30 turns from failed departure
Quote:
Originally Posted by eisnerrv4
First of all glad you're ok. 300 feet and a turn back to land. I was always taught that is a recipe for disaster. The classic stall spin to the ground. I know I wouldn't get away with that in the 4. Is this something that is safe in the 12?
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All: I know the mantra: engine failure on take off, land straight ahead and hit something soft. I submit that that is certainly good advice about a Cessna, Piper or other conventional spam can. And landing straight ahead at 1.3 VSO beats stalling 200 feet in the air.
And some sacrilege: my 1986 RV4 wood prop (no constant speed disk drag) has a wing loading at gross of 13.6 pounds; a power loading of 9.3 pounds per hp; and a pretty high roll rate. At a typical climb speed of 85kts, it is about 40 kts over stall speed...assuming 1.5 seconds to perceive and react, my strong sense is you can hit 300-400 feet, detect failure, roll, decel to 60 kts, do the 210/30 turns and get back to your lift off location. I know it can be done from 500 feet with plenty of excess altitude because I have done it with a vapor lock from an "all metal life time warranted fuel hose". I vividly recall rolling wings level on short final thinking how much energy and altitude I had left and how any other plane I had flown would have planted me in some trees or vineyards...What an amazing plane! 300 calls for some quick thinking, but those houses in front might be a pretty strong incentive to make a rapid 45 degree banked roll, drop the nose to maintain 60, drop full flaps, and worst case, park it on the airport property. most likely, you hit the runway, my guess.
The 4 has so much more performance than a spam can that the prescriptive rules really are different (at least for me). Not saying you cannot stall spin yourself: a partial list of people I knew personally who have done it in RVs include Arlen Pestes, Randy Pexton, Bill Bruce, Bill Paragin, Mack Johnston...and you can land straight ahead into a car/house/tree/powerline and have the same outcome. I think the best thing to do is focus inside plane because the physics variables are pretty baked in the cake: maintain 60 kts till you are out of the steep turns, wings level, slow to 50 kts and hope there is runway under the wheels.
So, we know from this video that an RV12 with a somewhat delayed response and maybe a little residual power can make the 210/30 from around 300 feet. I know my 4 can do it from 500 when it is fat with fuel and bodies, and starting from a 85 kt climb. Not interested in starting a fight about one of the sacred cows of light plane operation. Maybe it is the case for the majority of pilots in the majority of spam cans, park it straight in front is the best advice. MTCents J
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