Commercial - discontinuance

traumachicken said:
Would they really want to see that?
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My DPE actually talked about it during our emergency descent, he said "so what if you had the airplane clean and weren't sure if you were going to make the glide to your chosen emergency landing spot?". I said, "well assuming we still had some oil pressure, we could pull the prop back and reduce drag". He said "OK, show me". So I did. I did not do it on the emergency landing though.
 
Mike H said:
One thing you can do on the power off 180 if you seem to be coming up short is pull the prop all the way back to low RPM. It cuts drag like feathering the prop does on a twin. Just remember to push it back in if you need to go around
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Bad bad Idea.....I have a method that was taught to me by an ole RAF guy years back, I'll see if I can get a graphic on here for you, it works 100% of the time...
 
rframe said:
My DPE actually talked about it during our emergency descent, he said "so what if you had the airplane clean and weren't sure if you were going to make the glide to your chosen emergency landing spot?". I said, "well assuming we still had some oil pressure, we could pull the prop back and reduce drag". He said "OK, show me". So I did. I did not do it on the emergency landing though.
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In real life, I agree it is a GOOD idea, but not a good idea in the training environment, it's an accident/incident waiting to happen....Even better in real life would be to slow up enough to get a dead stick, that's the best reduction in drag you'll get, since it's entirely possible that you won't have the ability to get that prop into the full coarse position. IMHO if you need measures like this to make it happen, then you are not ready for the manuever in the first place. Your planning, judgement and stick/rudder skill may still need work....IMHO
 
Ziggyfuzz said:
In real life, I agree it is a GOOD idea, but not a good idea in the training environment, it's an accident/incident waiting to happen....Even better in real life would be to slow up enough to get a dead stick, that's the best reduction in drag you'll get, since it's entirely possible that you won't have the ability to get that prop into the full coarse position. IMHO if you need measures like this to make it happen, then you are not ready for the manuever in the first place. Your planning, judgement and stick/rudder skill may still need work....IMHO
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I would be careful about teaching the stop-the-prop routine. It does lower drag, but in some airplanes you have to get very slow to stop an already rotating prop. My primary instructor was big on them and I've got about 4 pages of logs flying dead head legs from aerial photography missions where he'd always have me stop the prop and glide back with a dead stick spiral to land, I remember these well and he liked to write the comment "glider time" in my comments. Getting slow enough to stop the already turning prop on something like a 172 is very slow and I'd often have the stall horn blaring to get it to stop. So then there is a resulting dip to get back up to glide speed. We were up high doing this, it's the last thing I'd try to extend a lower level emergency glide.
 
I didn't say anything about teaching that...just that it would be appropriate in real application if you had to. I just don't see the point in doing those "exercises" that you describe above. What is "he" or anyone else trying to prove to themselves??? Unnecessary risk taking...without a cause is reckless...

As a DPE myself, I had a guy on his CASEL doing the power off 180 use a little "bump" of flaps to make it over the dirt and on to the threshold one day. I applauded his seat of the pants understanding and use of the tool, but cautioned him that he should be able to make it work without that. The nice thing is as a CFI, you'll probably get real good at it, then it's like riding a bike...
 
rframe said:
I would be careful about teaching the stop-the-prop routine. It does lower drag, but in some airplanes you have to get very slow to stop an already rotating prop. My primary instructor was big on them and I've got about 4 pages of logs flying dead head legs from aerial photography missions where he'd always have me stop the prop and glide back with a dead stick spiral to land, I remember these well and he liked to write the comment "glider time" in my comments. Getting slow enough to stop the already turning prop on something like a 172 is very slow and I'd often have the stall horn blaring to get it to stop. So then there is a resulting dip to get back up to glide speed. We were up high doing this, it's the last thing I'd try to extend a lower level emergency glide.
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How is that even legal? Possibly one of the craziest stories I have ever heard. Im assuming he pulled the mixture, throw it back and it will fire, but What happens if it doesnt come back when you need it? I am sure that would have gone well with the NTSB.
 
traumachicken said:
How is that even legal? Possibly one of the craziest stories I have ever heard. Im assuming he pulled the mixture, throw it back and it will fire, but What happens if it doesnt come back when you need it? I am sure that would have gone well with the NTSB.
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Somebody asked him that once and he said something like "well where do the FAR's say you have to use the engine?". Then he'd say it's safer than a glider which has no engine at all to start if you need it and we had better glide performance than Bob Hoover in a twin with two stopped engines... It sounds more dramatic than it really was, we'd typically arrive at the airport with a few thousand feet to spare, spiral down, land and roll to the ramp... the goal was to not have to start the engine to make it to parking (ramp was right on the end of one runway). Call it reckless if you want, but I found it helpful training on energy management and SA and I gained lots of confidence in handling a power out landing. That all said, I'm not endorsing it and wouldn't recommend it to anyone. The point is, I do not recommend thinking about stopping the prop for a better glide unless you're up high because to do so you'd be putting yourself close to a stall condition when you're already trying to manage an emergency... so, if nothing else, the experience helps me to know that a textbook answer isn't necessarily a good idea, because I've seen it.
 
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