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RV-12 Engine off landing - Stall

J

JBPILOT

Well Known Member
http://www.youtube.com/watch?v=zK_sCcoeStI

Great day in Iowa today. Video shows an 'Engine off landing', followed by an 'engine idling stall'. Camera was mounted in passenger seat, up high. The stall does not look as serious as it seems in the plane. Cool air, it recovered in about 2 seconds. Was about 25 degrees today in Iowa. Winds were about 3 MPH, Gusting to 4 MPH ( HA ! ).

John Bender
 
wow... thats pretty ballsy... Idk about everyone else but I'd feel real uncomfortable shutting it all the way down while still in the air...

Where I'm from deer or birds could be crossing or on the runway at any given moment and I'd like the ability of doing a go-around if possible...
 
Appreciate the concern, but - -

Start it up ! Starts in 1 second. I could see for miles. I could have started it at any second. Did you see how fast it started once I landed ? ?

John Bender
 
Engine off sure takes out the camera shake :rolleyes:. Pretty cool (and good training of course). Man it looks cold up there!

Thank you for posting.
 
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John, that was great, in all my training never did a power off landing. It was always at least pattern alt. pulled to idle in the rental 172R. My instruction school would not consider letting shut the power off. Mark C.
 
very true John. It's interesting to hear/see an RV turn into a glider! I think it's just something inside me that gets creeped out knowing that I turned a perfectly good engine off on purpose.... LOL
 
SERIOUSLY - -

You really need to know what to expect if the engine shuts off on its own. The prop not turning creates drag, and changes the glide slope a bunch. I am lucky. I am at an all new airport with a 5500' X 100' new concrete runway. As you could see, I gave myself a LOT of margin. Landed about half way down it. BTW, I didn't use the flaps, but could have when I knew I had it made. Actually, I wanted to see how much further I could go with flaps up.

John Bender
 
Engine Off

Cool Video !!!

My instructor made me do engine off landings. We'd usually start off at about 5,000 - 6,000 agl turn the engine off and pitch up to stop the prop. and then orbit the field. Became routine after a while. It was easy since it was an old WW2 Army Air Force base in Palacios, Texas. Lots of pavement and Rattle snakes.



Gary
 
Great video, thanks for sharing all that. I only hope I have the balls to try that on mine after all that work putting it together.
 
Data Download?

John, you didn't happen to pull the data off the Dynon for the engine-out flight, did you? It would be interesting to see the airspeeds, descent rates, pitch-down, etc-.

Oh yeah, and the CHT's. Shutdown on a cold day behind an air-cooled engine would've been a good excuse to exercise the old dye-penetrant spray kit.

Jim in South Texas
RV12 #120264 flyin' thru the test cards
 
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Hey Jim - -

No, I didn't pull any data off. I can pretty much tell you what I did. I was going about 80 kts when I turned it off. I found out that if you are not going that speed or lower, the engine does not stop - just keeps on turning. I maintained about 75 kts most of the way on base and final. I cut the normal pattern shorter than usual to allow an extra margin of alt. As you can see, I had plenty. I started out at pattern alt, about 800 feet up. NOTE : I did not use flaps. I could have shortened the landing spot if I had. I also flared a bunch and fell the last foot which I usually don't do, but wanted to get slowest speed before touch-down with flaps up. It is surprising how much air noise there is with the engine off. I may do another video and try to maybe put flaps down on short final, just before touch-down.

If your airport has a slow time, it is a good thing to practice. This engine starts in a second, so no real problem if landing short or long.

Forgot - yes it cools down a fair amount even in a short time when it is 25 degrees. The water helps control the cool-down rate. Not a problem.

John Bender
 
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Just a few words of caution about shutting down the Rotax 912 engine in flight.

I would advise to shut the engine down closer to stall to avoid free wheeling. As John found out it will keep turning in flight (free wheeling) at higher speeds. Conceivably, you could flood the engine if it keeps turning with no spark making a restart "interesting", or you could have a loud and dangerous explosive backfire in the muffler and exhaust. :eek:

Make sure you have the engine ready to re-start. As soon as the engine stops turning switch the ignitions (mags) back on to hot. The Rotax 912 ignition system will not fire under 200 RPM. It won't start with just a blade or revolution or two as John's video shows. Then, if you need to restart all you have to do is turn the key. The engine should be running before you can remove your hand from the key.

Also, IMHO you should use the same landing configuration as you always do. If you use flaps when landing use them when gliding. Aim for the middle of the runway, not the numbers. Leave yourself room to learn the glide characteristics. It is MUCH different than an idling engine.

Practicing dead stick landings will make you a better pilot, and you will learn how to survive if you have an engine out..... #1 Rule: FLY THE AIRPLANE! #2 Rule: Refer to Rule #1. ;)

Good work John! Keep those videos coming!
 
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Also, IMHO you should use the same landing configuration as you always do. If you use flaps when landing use them when gliding. Aim for the middle of the runway, not the numbers. Leave yourself room to learn the glide characteristics. It is MUCH different than an idling engine.
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I'm going to disagree on this advice. It's important to be able to hit a target on a dead stick landing since most fields and golf courses that you would realistically have to put down in are not 5000 feet long. If you can master the slip then you can put that bad boy in a parking lot if you had to.
 
Totski said:
I'm going to disagree on this advice. It's important to be able to hit a target on a dead stick landing since most fields and golf courses that you would realistically have to put down in are not 5000 feet long. If you can master the slip then you can put that bad boy in a parking lot if you had to.
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understand your thinking and I agree that the slip is something you need to master with this airplane. that said, if I lose an engine anywhere near a runway I will immediately turn to the runway (or golf hole) and deal with altitude over the runway, not in front of it.

pete
 
Another good day in Iowa - -

http://www.youtube.com/watch?v=hXaVOFQqG_g

Built a different camera mount, and tried a couple more Engine off landings. I think it worked a little better. Still surprises me how much wind noise there is with the engine off. This time I kept the speed between 55 - 60 kts. Turned the prop a little less. Need to be about 55 kts to stop turning it. 1st time I forgot to turn the mags back on, and you can hear that. Engine still starts in a second. Was fun. Was 40 - 42 degrees today in Iowa. Not bad ( today that is ! ).

John Bender
 
Very nice John. Smoother landings than the other day. I too am surprised by how much air noise is present. I wonder what the predominant source of that noise is and whether there is any way to dampen it some.
 
JBPILOT said:
http://www.youtube.com/watch?v=hXaVOFQqG_g

Built a different camera mount, and tried a couple more Engine off landings. I think it worked a little better. Still surprises me how much wind noise there is with the engine off. This time I kept the speed between 55 - 60 kts. Turned the prop a little less. Need to be about 55 kts to stop turning it. 1st time I forgot to turn the mags back on, and you can hear that. Engine still starts in a second. Was fun. Was 40 - 42 degrees today in Iowa. Not bad ( today that is ! ).

John Bender
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I think John is just learning to cut the engine off in the pattern to save fuel. ;)


John, the next step is to go up 4,000' AGL over the airport and cut the engine. Then you have to judge sink rate, distance, altitude, ect. Very fun.
 
Well Larry - -

I'd just dive for the end and float for 5500 feet ! ! ! ! :D That would cool the engine down for sure. A minute of two does not cool it that much. The heater cools, but the oil is still good. I might do that if no one is around the pattern. Could always start it, and get out of someones way. Challenge accepted ( someday ! ! ! ).

John Bender
 
John

Next time you do some engine out work. Set up your Garmin to show the glide ratio.



Brad
 
Hey Brad - -

Didn't even know you could do that ! ! Back to the book I guess ! ! Thanks Brad,

John Bender
 
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