My first dead stick landing.

[danny_galaga]

So today I went for a little flight. Approaching moogerah dam, I decided to go down lower to enjoy the scenery. I wanted to descend fairly quickly so I shut the throttle on my 912uls. Oh, it will only go down to 3200. Hmmmm. I had moment where I found myself thinking 'is that normal?' and then logic kicked in to remind me that 2000 is what I'm looking for when descending into the base turn.

 

In the past I've thought about what I would do if my engine went wide open throttle due to a broken cable or whatever. So I already had some things to experiment with. First of course, I open and closed the throttle a couple of times to see if it would 'come good'. It didn't. So then I started to put the choke on, see how far I could get it. Turns out pretty much all the way on in flight. The Bing carby doesn't use a butterfly for a choke, it just opens up a different fuel port, which richens the mixture that way. Then I turned one ignition off. I reduced the revs roughly 400rpm like this. In a real WOT situation, that could be the difference between shutting the engine down straight away or buying some time to get to a landing area. With my plane, WOT would most likely exceed VNE. 400 rpm off might be ok. Something to bear in mind (if I had to do that for more than a few minutes, id alternate switches every 5 minutes, and also let it run with both on and no choke for a few seconds every so often)

 

Anyway, once I'd established what I could do, I turned both ignitions back on and closed the choke. When I made my overhead airfield call, I added that I would probably be dead stick. I did the circuit as normal. But obviously a bit fast downwind, turning to base and final. Luckily I was still in the white arc so I could go full flaps. On final I did my trick with the choke and ignition. I got it to about 10knts above the usual 50ish. When I was absolutely sure I could make it, I killed the ignition. Interestingly, I have such a big stupid three blade prop that it just kept windmilling. So fast I thought I must have left an ignition switch on! Even with some forward slip. Once it got down to about 50 the propeller finally stopped. 

The landing was uneventful. After starting again the taxi was a bit goofy because I was using my trick to keep the revs down. But with no air speed to help, naturally it ran a bit rough.

 

 So, even as I anticipate not flying anymore, I'm still learning!

 

What I think I did well:

 

Since I had already thought about a vaguely similar situation in the past, I knew immediately what I could try to bring down the revs. Also, I knew that since I couldn't be sure what was causing the problem, it was best not to play around with the throttle TOO much, lest it got worse. 

 

Alerting the field in the radio call sounds melodramatic, but it ensures that people know that I probably won't be able to go round, and that I might not be able to clear the runway immediately after landing. 

 

Kept calm. It's just a normal landing.

 

What I didn't do well:

 

I was rather preoccupied with how the aircraft would behave when the engine was shut down. And rather mesmerised by the windmilling prop. So much so that in retrospect, I wasn't flying in a deliberate and conscientious way. For instance, not thinking about aiming for the threshold, and then when rounding out, aiming for the infinite distance. I just kind of did it by muscle memory. I've found I am most conscientious about flying when I'm taking a friend. Because I describe to them everything I'm doing.

 

I was rather slow to get off the runway. Yes, it all worked out well, but let's get a wriggle on and not add a new hole to that block of Swiss cheese 🧀 

 

 

[facthunter]

The choke(so called on that engine) ONLY works when the throttle is closed to slightly open.  Cutting the switches will mean the Muffler will get full of combustible  mixture and putting them back on may ignite it and cause an explosion in the exhaust system, which will scare the $#!t  out of you even if it does nothing else. To stop props windmilling can require some extra work and Manoeuvering that I wouldn't suggest you do in any  RAAus Plane and certainly Not at Low height. This is an exercise in situational awareness that Legally should only be done with an instructor who is competent. Plan to land well into the field, because hitting the Near fence at flying speed is far worse than hitting the Far one at walking speed. There's always room to Learn more. Never stop Learning.  Nev

[danny_galaga]

16 minutes ago, facthunter said:

The choke(so called on that engine) ONLY works when the throttle is closed to slightly open.  Cutting the switches will mean the Muffler will get full of combustible  mixture and putting them back on may ignite it and cause an explosion in the exhaust system, which will scare the $#!t  out of you even if it does nothing else. To stop props windmilling can require some extra work and Manoeuvering that I wouldn't suggest you do in any  RAAus Plane and certainly Not at Low height. This is an exercise in situational awareness that Legally should only be done with an instructor who is competent. Plan to land well into the field, because hitting the Near fence at flying speed is far worse than hitting the Far one at walking speed. There's always room to Learn more. Never stop Learning.  Nev

Yes, I definitely wasn't going to emulate a Sopwith pilot 😄 I cut only 1 switch to reduce rpm. Once I knew I was in, I cut both to stop the engine. I wasn't trying to stop the windmilling, it's just I was surprised it was spinning as fast as it was. But my approach was fairly fast. Like I say, once my airspeed dropped, it stopped. Since the throttles were slightly open (after all, that was my problem) the choke was doing its thing. But I see what you mean, if it's a WOT situation, it probably won't do anything. I'll try that next time. I will do a little post on what caused the problem in the first place. 

Edited 11 hours ago by danny_galaga

[Blueadventures]

Good job, well done.  What was the issue, Is there a throttle lever on the passenger side/ If so could that be tried to reduce the rpm?

[Marty_d]

Well done!

[facthunter]

WOT will fill the cylinders and MAY help to stop the Prop spinning. Be better if no fuel was going in but that's not available to you easily. I wouldn't advise getting fixated on a stopped prop.  ALWAYS Keep a good eye on the shop. Nev

[danny_galaga]

56 minutes ago, Blueadventures said:

Good job, well done.  What was the issue, Is there a throttle lever on the passenger side/ If so could that be tried to reduce the rpm?

 

[Kiwi]

I heard your call and watched your landing,  you did a good job.

 

I was quite surprised that the rotax was windmilling, mine stops as soon as you kill the mags.