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| | #1 |
| Old Skool |
Hello I am currently working on my CFI certificate and I had a lesson today that involved practicing engine out in flight. One thing that kind of bothered me about my CFI was one of the steps he did was feather our prop. His reason was that it aligns the props directly into the wind thereby reducing drag and our VSI (rate of descent) was reduced by 100-150 feet. I was normally taught not to feather the prop especially during my commercial multi training and just to "sim feather" the prop. My take on it is not to feather it because if you still have power you want the windmilling prop to take as much chunks of air as possible. But if we did have a full engine power gone then I would agree to feather it. I checked the POH for the R182 and under section 3 it speaks nothing of doing anything to the prop. Advice, input and clarification greatly appreciated.-thanks!
__________________ -CP/MEL-IR;AGI -Former Airline Intern,Sightseeing tours pilot -A.A.:Trasnfer Studies. Cal-State Fullerton: Finance/Entrepreneurship -Sigma Phi Epsilon Fraternity.-Pledge/Sigma President |
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| | #2 |
| Junior Member |
Wait, are we talking about a multi or a single? Twins can be feathered (and in the event of an actual engine failure, feathering the prop is part of the "engine-out drill" - mixtures, props, throttles, flaps up, gear up, blueline, identify, verify, FEATHER...), but singles cannot. You said "I checked the POH for the R182...." The prop on a Cessna 182 (is that what you are referring to?) CANNOT be feathered. With that said, what I used to teach for engine-out in a complex single was you leave the prop control alone (and leave the engine windmilling), and try to plan your descent based on the performance you've got. Then, if on final to your field you are coming up a bit short, you can TRY to bring the prop to a coarse pitch (pull the prop control full back - this is NOT THE SAME AS FEATHERING THE PROP) and you will get an instant reduction in drag if it works. If it doesn't work, nothing will happen and you'll still end up short, but if you're gonna be short it's worth a shot. Anyway, that's my two cents on the subject.
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| | #3 | |
| Old Skool Join Date: Sep 2006 Location: Memphis, TN
Posts: 2,445
| Quote:
I'm a little fuzzy on your situation. You're flying a 182RG for your CFI training? If so, you can't feather that prop, you can only go to the low RPM stops and yes, this will reduce drag on the airplane. Some POH's make this recommendation and some do not, but it *must* help with every airplane. Note that reduced VSI alone does not demonstrate an increased glide range. Only a reduced VSI at a constant airspeed will do this. If this is what you saw, then it's pretty much irrelevant, IMO, what the POH says about it. The real world had greater authority than any printed literature. ![]() But you're right, if you're developing some power, you may be better off to leave the prop at a high RPM.
__________________ Core Concepts of Flight If an error is corrected whenever it is recognized as such, the path of error is the path of truth --Hans Reichenback | |
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| | #4 | |
| Old Skool | Quote:
yeah my mistake the 182 does not feather. But either way the 182 POH speaks nothing of touching the prop handle. And now that Ive talked with some helpful individuals and research its probably best not to, except if I knew I was not able to restart the engine or need to stretch out the glide more. Thanks for your input.
__________________ -CP/MEL-IR;AGI -Former Airline Intern,Sightseeing tours pilot -A.A.:Trasnfer Studies. Cal-State Fullerton: Finance/Entrepreneurship -Sigma Phi Epsilon Fraternity.-Pledge/Sigma President | |
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| | #5 |
| Senior Member Join Date: Oct 2007 Location: Ohio
Posts: 818
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Just keep in mind if you do lose the engine and lose oil pressure as a result, you may not be able to get the prop to the high pitch/low RPM setting. -mini |
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| | #6 |
| Old Skool Join Date: Apr 2002 Location: Denver, CO
Posts: 2,094
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Okay, I had to read that a couple times before I followed. When I read the word "feathered" in the title I was thinking twin, and of course you are going to feather it. Yeah, feathering a single...not so much.
__________________ "Roads?...Where we're going we don't need roads." |
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| | #7 |
| Senior Member Join Date: Jan 2003 Location: Low Earth Orbit
Posts: 1,389
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Shutting down and feathering a mulit for training.....fine Shutting down a SEL plane for training....unsat and a candidate for 91.13 If you are uncomfortable with anything a CFI does, I would consider a chat with his CP. |
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| | #8 |
| Old Skool Join Date: Sep 2002 Location: Grand Forks, ND (UND)/ Davenport, IA
Posts: 2,204
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You're not really "feathering" the prop persay, but what you are doing is bringing it to a high pitch/low RPM setting. This greatly reduces drag. I would NOT do this during training, at least not in an arrow(which is the complex single we fly here). I would definitely do it in an actual situation if I found myself coming up short, which was said before. Why I'm against it during training, is the possibility of forgetting to put it back in the low pitch/high RPM setting for the go around/recovery. I've never actually tried this, so I don't know what the actual result would be. I just know at UND, they do not recommend it during training, but in an actual engine out landing, go ahead and do it if you're coming up short.
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| | #9 |
| Junior Member |
Coarsening the pitch of the prop was the normal procedure during simulated engine failures when I used to fly the Arrow. It wouldn't feather, of course, as it wasn't designed for that. But any reduction in the windmilling of the prop is good for one thing: giving you more time to troubleshoot and find a suitable spot for a forced landing!!
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| | #10 |
| Senior Member Join Date: Jul 2007 Location: Little Rock, Arkansas
Posts: 418
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no, certainly the single's constant speed prop cannot be feathered, only go to the low rpm stops. my recommendation is to always read the manual for your particular airplane to see what the appropriate procedure is in this case. if there's an advantage, the manual should suggest it, otherwise i'd worry little about this and concentrate on slowing to best glide,picking your landing spot, trying a restart and taking steps to prepare for a forced landing. in general, if unsure, if it's a partial power loss, leave it at high rpm..if it's quit completely with no restart, it won't hurt to pull to the low rpm stops, but doubtful you'd see much advantage..too may variables in an emergency. survival is your priority.
__________________ Gold Seal CFII, MEI, AGI, IGI, ATP, LR-Jet |
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| | #11 |
| Senior Member Join Date: Jan 2003 Location: Low Earth Orbit
Posts: 1,389
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Let me add something else to consider. More than likely, you are wasting time/safety practicing something you won't have any control over anyway. I have seen several failures in SE airplanes. You are likely to have a broken crank, cracked cylinder, complete loss of a cylinder, broken prop, missing blade/prop and the list goes on. You have a high probability that you will not be able to control the prop at all and may likely have MORE drag than normal. Either way, shutting down an engine in a SE airplane is not a "simulated" emergency.
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| | #12 | |
| Old Skool | Quote:
I know we're talking recip singles, but just be careful saying no singles can be feathered. Some can be and are, while not being emergencies. | |
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| | #13 |
| Junior Member | |
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| | #14 | ||
| Old Skool Join Date: Sep 2006 Location: Memphis, TN
Posts: 2,445
| Quote:
![]() Quote:
![]() Remembering to push the prop forward before applying full-throttle is a good habit; I ensure the student does it when we're practicing engine-out procedures.
__________________ Core Concepts of Flight If an error is corrected whenever it is recognized as such, the path of error is the path of truth --Hans Reichenback | ||
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| | #15 |
| Senior Member |
The aircraft that I'm flying now (T-6 Texan II) is a complex single engine prop, and for our engine out emergency training the "Book" lists a particular throttle setting (4-6% Torque) which is the supposed to be the equivalent of a feathered prop. That's the setting we use during our simulated engine out scenarios, and we also use that setting in actual engine emergencies where the engine hasn't completely quit but we expect that it may. In an actual emergency (like a loss of oil pressure or a chip light or something,) once you get "on profile" for a successful engine out glide to a landing we retard the throttle so that you don't build too much energy, but if you still have the engine and start to get low again, you can give yourself a little boost. I don't know if there's an easy way to figure out the throttle setting that would result in the same performance as an engine out with prop feathered, but if so, the CFI could just set that.
__________________ Dude, what are you trying to do? Land the airplane or adjust the field elevation? |
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| | #16 | |
| Senior Member Join Date: Jun 2007 Location: KAUG
Posts: 511
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| | #17 | |
| Old Skool Join Date: Sep 2002 Location: Grand Forks, ND (UND)/ Davenport, IA
Posts: 2,204
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I do at least tell my students about this as an option, so I'm not totally leaving it out.
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| | #18 |
| Senior Member Join Date: Oct 2007 Location: Okinawa, Japan
Posts: 302
| I did my CFI check ride in an Arrow. The engine failure during flight check list says to bring the prop to low RPM, so that's exactly what I practiced. Once during the go around I nearly put the throttle forward with the prop still back, so I developed the technique of leaving my hand on the prop lever throughout the maneuver until I had returned the prop to high RPM. (I still use and teach this technique today.) When the FAA examiner gave me a simulated engine failure during my check ride, I used the procedures I had developed, but she had a conniption. She got so upset at my bringing the prop to low RPM that I thought I was going to fail for it. She told me it was hard on the engine and I should do it once for training and after that just simulate bringing the prop to low RPM by adding 1" of MP instead. She brought it up again after we landed, and I showed her the AFM. I told her that even if it was hard on the engine, in my opinion there were three times to actually do this step in the checklist instead of simulate it with MP: 1. Once for training, as she suggested, so a pilot could see what the difference actually is, 2. During an actual engine failure, 3. During an FAA check ride! She didn't fail me for this procedure but was still upset an hour afterwards. She gave me the "I'm going to have a talk with your Chief Flight Instructor" line. I told my chief about it and he laughed. The examiner called me later to tell me that she was wrong (it wasn't hard on the engine as she had feared) and that the technique I had developed by keeping my hand on the prop while it was in low RPM was fine. |
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| | #19 | |
| Senior Member Join Date: Jul 2007 Location: Little Rock, Arkansas
Posts: 418
| Quote:
__________________ Gold Seal CFII, MEI, AGI, IGI, ATP, LR-Jet | |
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| | #20 | |
| Old Skool Join Date: Sep 2006 Location: Memphis, TN
Posts: 2,445
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Anyway, here's what the certification regulations say on the matter: § 23.71 Glide: Single-engine airplanes. The maximum horizontal distance traveled in still air, in nautical miles, per 1,000 feet of altitude lost in a glide, and the speed necessary to achieve this must be determined with the engine inoperative, its propeller in the minimum drag position, and landing gear and wing flaps in the most favorable available position.
__________________ Core Concepts of Flight If an error is corrected whenever it is recognized as such, the path of error is the path of truth --Hans Reichenback | |
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| | #21 | |
| Senior Member Join Date: Jul 2007 Location: Little Rock, Arkansas
Posts: 418
| Quote:
__________________ Gold Seal CFII, MEI, AGI, IGI, ATP, LR-Jet | |
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| | #22 |
| Old Skool |
Wow thanks guys for the experience and reference. I myself was unclear and kind of want to leave it in high RPM especially during simulation in SE operations, unless it was total failure. but thanks agian for claryfying it.
__________________ -CP/MEL-IR;AGI -Former Airline Intern,Sightseeing tours pilot -A.A.:Trasnfer Studies. Cal-State Fullerton: Finance/Entrepreneurship -Sigma Phi Epsilon Fraternity.-Pledge/Sigma President |
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| | #23 |
| Senior Member | |
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| | #24 |
| Old Skool Join Date: Sep 2006 Location: Memphis, TN
Posts: 2,445
| My copy of CAR 3 does not show any requirement for glide ratio information.
__________________ Core Concepts of Flight If an error is corrected whenever it is recognized as such, the path of error is the path of truth --Hans Reichenback |
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| | #25 |
| Senior Member | Where could I possibly get a copy of CAR 3? Is is available online? I ask because I have a checkride coming up soon that will be in a CAR 3 airplane and would like to be able to reference information if needed.
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