Multiengine Dilemma

flyingcheesehead said:
Henning,

How about this method? Add power for takeoff, hand positioned on front of throttles to retard in event of failure. When chop and drop is no longer an option, move hands to prop levers to prepare for identifying.

I thought it was possible to un-feather a prop too, if the associated engine is running? :dunno:
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When rolling, my hand is on the throttles right until I'm about to rotate, then I switch them to the props. As to unfeathering, that depends on the aircraft and if it has unfeathering accumulators installed. It takes oil pressure to be able to get the blades off the locking pins. The drag of a feathered prop may very well stall the engine. No matter though on a rotational emergency, there is no time. At altitude the whole arguement is moot. The only place it matters is those first few seconds between red and blue line where you have to accellerate after losing approx 80% of your reserve power and have no altitude to trade for speed. In that transitional range, everything counts and it all has to be spot on with anything less than a King Air.
 
flyingcheesehead said:
I thought it was possible to un-feather a prop too, if the associated engine is running? :dunno:
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Not from 30 feet agl.

My response to all this, besides generally flying 200 undergross (less than 5000 feet), is that if you feather the wrong one you are screwing the pooch for sure, as in four seconds to impact. If you coarse pitch the wrong one it does take a good two seconds for the now Eng.Inop. aircraft to regain OEI power. Crump.

If you half pull power from the wrong engine, in a split second you have full power again. Get it right.

Get it right. Adopt runway management strategies that you know are going to work for your skills. And do the pre departure briefing every time. It saves most of that critical three seconds of "duh" time.

Didn't we just have an Aztec driver who survived this sort of situation...though crumped the bird?
 
Didn't we just have an Aztec driver who survived this sort of situation...though crumped the bird?
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Yes, that was me. I've been following this thread with interest. It is an interesting concept that was never shown to me. I am not sure if it is a good or bad concept. Surely if you get the right prop lever the first time, it would save time, but with someone with somewhat less than stellar skills, such as myself, it could end up disastrous. We were well under gross on a bird that we thought would fly off on one engine, but with the gear still going up, the low airspeed and the switching of controls, we had NO TIME to identify and feather at all before the airspeed went down further. The only option was to set it down NOW. I keep grilling myself that I should have been faster at recognition and recovery.

Maybe it at least merits some checking in training.
 
Aztec Driver said:
Yes, that was me. I've been following this thread with interest. It is an interesting concept that was never shown to me. I am not sure if it is a good or bad concept. Surely if you get the right prop lever the first time, it would save time, but with someone with somewhat less than stellar skills, such as myself, it could end up disastrous. We were well under gross on a bird that we thought would fly off on one engine, but with the gear still going up, the low airspeed and the switching of controls, we had NO TIME to identify and feather at all before the airspeed went down further. The only option was to set it down NOW. I keep grilling myself that I should have been faster at recognition and recovery.

Maybe it at least merits some checking in training.
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The key in my opinion to getting it right everytime is practice the opposite foot/finger (I have one finger on each handle) relationship until it's muscle memory. It paid off one evening in a 310. The wildcard is how long it takes your brain to accept what is happenning.
 
Henning said:
As to unfeathering, that depends on the aircraft and if it has unfeathering accumulators installed. It takes oil pressure to be able to get the blades off the locking pins. The drag of a feathered prop may very well stall the engine. No matter though on a rotational emergency, there is no time.
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I should have clarified that I didn't mean the unfeathering would occur down low... It was just kind of a general question.

So, without unfeathering accumulators, how do you get the prop in useable condition again? I'd have thought that if you can get the engine running, it'll have the oil pressure to unfeather the prop. Is this wrong?

I got to observe a training flight on a 414 where the instructor-pilot pulled the mixture on one engine. It appeared to be very difficult to get that engine started again. The trainee did get the prop feathered.
 
flyingcheesehead said:
So, without unfeathering accumulators, how do you get the prop in useable condition again? I'd have thought that if you can get the engine running, it'll have the oil pressure to unfeather the prop. Is this wrong?
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Correct, if you get it running, you have oil pressure. Once you feather, you have to use the electric starter motor without the accumulator to restart. With the unfeathering accumulators, when you bring the handle out of the feather detent, the accumulator unloads oil into the prop which unloads the spring/blade pressure from the pins so they can retract, the prop can go to fine pitch, and the engine windmill to a start. This is why ME trainers are often equipped with them.
 
flyingcheesehead said:
I got to observe a training flight on a 414 where the instructor-pilot pulled the mixture on one engine. It appeared to be very difficult to get that engine started again. The trainee did get the prop feathered.
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The 414 has injected engines...hot starts on injected engines, while not truly difficult, cause problems because people just can't figure out how to do it.

I finally read the article that prompted this thread...I find it interesting that the article starts off with the premise that the abort technique is not properly spelled out in POH's, the AFH, training, and wherever else. The answer then, as it appears to me in the article, is not to abort. hmmm...

Fly safe!

David
 
MauleSkinner said:
I finally read the article that prompted this thread...
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Do you have the title of the article or perhaps a link ? I came into the discussion mid-stream.
 
jdwatson said:
Do you have the title of the article or perhaps a link ? I came into the discussion mid-stream.
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It's from the recent AOPA Instructor Report...it's sent out to all CFI's, I believe. Not sure if you can access it through the AOPA site.

There's a LONG thread on flightinfo.com about this, started by the same guy.

Fly safe!

David
 
Ron Levy said:
I can't speak to all twins, but there isn't one in a Cessna 401, Piper Apache, Piper Aztec, or Grumman Cougar, those being the only light twins in which I have any significant experience.

Absolutely not. I am, and I teach trainees to be, very deliberate about the identify/feather drill.
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dont know what 401, apache or Aztec you were flying but there is a detent or at least added friction corresponds to about 2100 rpm, if fact i cant remember any twin other than 18s with hammers and pumps, that dont have one.
 
V1 is really only for Large transport catergory airplanes. And yes if you lose one on the ground but after V1 your still going.
 
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