Stopping your engine in flight

Last month I finally climbed up over the airport a few thousand feet and pulled the mixture to cut-off position. I then slowed the plane down just to the edge of stall to get the prop to stop. I then increase speed to 90 mph and glided in to land. Yesterday I climbed up to 8000' and pulled the mixture back. I was 10 miles out from my airport and by the time the altimeter hit 2000' I knew that making the field would be no problem. I figured I could get a mile for every thousand feet of altitude, wind does need to be factored in, but actually doing it was a great learning experience. I figured that putting the plane in a dive would make the prop start windmilling again to start up, it wasn't the case, but I only got up to 135 mph. I can't really think of any reason why there would be harm to the engine but I thought I would ask if there is anything I should be aware of before doing this again. Maybe shock cooling?

Randy
8A
0-360

To each his own, not my idea of good risk management.

Pat Stewart said:

To each his own, not my idea of good risk management.

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Interesting. Why don't you think it isn't good risk management?

I was thinking just the opposite. Here's a chance to see how your plane actually flies when the prop stops and learn from the experience. Restarting, if necessary, is not a 100% certainty, but pretty close to it. Add to this, the OP started above his airport where a dead stick landing was always an option before he moved off and glided back it. In my opinion, every pilot should be able to manage a dead stick landing. It can reasonably happen and the only way to prepare is to practice for it. I think the OP was doing exactly this.

It seems wise to me to prepare for the range of events you might encounter flying and to do so incrementally so you don't get in over your head.

What are the odds of the unprepared pilot dealing with a seized engine 10 miles out from an airport compared to Randy's odds? If I was the GIB, I'd rather be flying with Randy (or another pilot I know who does this).

what you are doing is standard procedure in a ximango motor glider that i used to fly. it took a lot of speed to get the motor turning over but viola she came to life. sounds like you need to get some real glider time. a glider add on is easy to do. glide on!

Congrats on first dead stick landing

Interesting first feelings Randy, isn't it? Adrenalin rush and excitement after touch down. Good add-on to your bag of flight experience. You will find a lot of theories about shock cooling but I wouldn't worry about it. Keep mastering those dead stick landings it makes you better pilot and keeps out of boredom

Pat Stewart said:

To each his own, not my idea of good risk management.

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I disagree totally. You have to know what's going to happen when and if the engine quits. This is totally right for testing your airplane. Done over a good landing site, absolutely.

And what about your engine's response to lack of fuel in a tank or the boost pumps? Run a tank dry and see how easily it restarts. Basic test flight procedures.

As for shock cooling, I wouldn't and don't worry (-320, 360, 540 series). What happens when you fly though rain?

Once you stop the propeller you have to assume you are in a real dead stick. If you stop the prop you have to assume there is a chance the starter will not engage (due to failure) to start the engine.

There are a number of ways this could happen unexpectedly in flight... Such as, what happens if you are practicing stalls and the engine quits in the stall entry and the prop stops? OK, recover from the stall, fly the plane and start the engine. What happens if the starter had it's last start at the beginning of the flight that day, and now does not work? Or if you were slow on your fuel selector management, run a tank dry, and you get slow while messing with the tank selector and the prop stops before you get the engine running again and then the starter poops out. OK, it can happen I guess. So there you are with prop stopped and no starter. Here is a last ditch possibility and I had this demonstrated to me by my primary flight instructor. Once your emergency field is made and you are flying toward it, a last ditch effort to get the prop turning is to speed up to 115 kts or so then pull about 2G positive to recover from the dive. As I recall, the gyroscopic precession of the 2G pull up acting 90 degrees to the prop will get the prop to swing just enough for the air to then force the prop to windmill again. Mixture rich... and back to powered flight (hopefully). This was demonstrated to me in a C-172 with a 180HP engine and fixed pitch climb prop (fine pitch). Constant speed props may be different enough to make a big difference on suitability for this maneuver and the airframe difference would be a big variable as well.

Please, no one try this without a really good idea of what you are doing or a CFI who is current and qualified on the engine and prop and knows what he/she is doing if you are not used to the training and flight test environment where this sort of thing is typical. My comment is only based on my memory and this was 24 years ago. A good plan and brief along with a qualified CFI who is current will go a long way though. Always have a few outs and backup plans in case someone else out there does something stupid. I think experiencing things like this or at least contemplating them are what makes "true" experience and it's valuable as long as it is approached properly (I assume you pre briefed and thought it all out with contingencies before you conducted your experiment, and I'm sure you learned a lot from it including the riskiness of risk!)

I have no comment on the engine implications in this case aside from my experience in being a CFI in certified light twin training years ago with 0-360's and 0-540's and constant speed props. I would simulate engine failures in flight by shutting off the fuel selector and we would run around for 10 to 15 minutes at a time training on OEI flight. The longer you cold soak an engine in flight with the prop stopped the harder it is to start. But even a cold soaked engine would start well on a Beech Duchess with prop accumulators what would unfeather and swing the prop enough to windmill it. Once it was windmilling we could easily start it with mixture, unlike other light twins with starters only (the starter would not get the motor windmilling on those as the prop was still feathered until the engine was running).

I'm with you Pat

If the engine quits unexpectedly I will put it on the ground if I cannot get it to restart - there is no mystery there. It is an airplane after all and it will glide. Having done it a few of times for real I can assure you that the the most pressing requirement is not flying the plane - that is instinctive. The need is to have a procedure to go through to attempt a restart - In all my cases this was accomplished by switching tanks and turning on the aux (boost) pump while the propeller is windmilling. I had one case where the engine lost its oil and any power being produced was a mystery but it seized completely on the landing rollout at Chino.

The greatest value in this thread is that the tester verified that some RV will glide and that he was unable to achieve a restart even though he tried. My goodness we have pilots that are learning to fly in the RVs they built and others fretting over flap use in landing. Even implying that all REAL PILOTS should shut down their engine and attempt a dead stick landing as good risk management is incredible. If they took this seriously we would have RV's down all over the place. If you want to do it, that is your business but to suggest that it is something that everyone should do is irresponsible I believe.

As far as the initial question is concerned - if shock cooling is a problem, it would certainly seem to apply in this scenario.

Bob Axsom

I did this a couple weeks ago in the 172 (IO360 FP), I had to get the airspeed back up to almost 140 before the prop would start windmilling again, that produces a rather alarming down-angle if you aren't ready for it.

As for shock cooling the engine, if you're going to do this just be smart about it. I reduced power incrementally to idle over a few minutes to let the CHT's come down smoothly and at a reasonable rate before killing the engine, likewise on the restart you don't want to go to full power immediately unless you're out of altitude. When I did it, I was returning from a cross-country and pulled the mixture at 12,500' and about 6 miles out, and the restart was around 5000' at idle power for the rest of the spiral descent to my runway. Be prepared for a failed restart, it can happen for a variety of reasons. Put yourself in a place where it can be an interesting story to tell, rather than an insurance seminar.

This is one of those things that I believe will make you a better pilot - if you understand the physics of what you're doing and the risk management skills are there. It's definitely not for all pilots and would result in a bunch of accidents like Bob said if we asked all pilots to do it. I know several pilots that are barely competent enough to find the mixture knob, let alone know what it does - those guys have no business getting outside of well-charted territory.

Risk vs Reward

I'm firmly in the camp who thinks practicing real emergencies is too much risk for too little reward. Although you may be within gliding distance of your home airport, what happens if the runway fouls when you are on short final or there's some other need to make a go around? I am also a glider pilot, but I wouldn't consider shutting down an airplane motor in flight. If I'm on short final in a glider and the runway fouls, I close the spoilers and the immediate reduction in drag gives me options. How long would it take you to make a go around from an intentional dead stick landing?

Other than learning what airspeed it takes to stop the propeller, I don't see what is to be gained from this experiment. A windmilling prop produces more drag than a stopped one does, even with the engine at idle. If you have the skills to land the airplane with a windmilling prop, then you can apply those same skills to land if the engine ever quits for real.

Nihon_Ni said:

A windmilling prop produces more drag than a stopped one does, even with the engine at idle. If you have the skills to land the airplane with a windmilling prop, then you can apply those same skills to land if the engine ever quits for real.

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Except that, as you pointed out, the drag is very different. If you've practiced engine-outs a hundred times with a windmilling prop, and have an engine seize up on you one day in flight and try that very same approach, you'll have too much energy as you approach the field because you have less drag. There is no one-size-fits-all solution here, other than being fully mentally-engaged in what you're doing.

Bob Axsom said:

The greatest value in this thread is that the tester verified that some RV will glide and that he was unable to achieve a restart even though he tried. My goodness we have pilots that are learning to fly in the RVs they built and others fretting over flap use in landing. Even implying that all REAL PILOTS should shut down their engine and attempt a dead stick landing as good risk management is incredible. If they took this seriously we would have RV's down all over the place. If you want to do it, that is your business but to suggest that it is something that everyone should do is irresponsible I believe.

Bob Axsom

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Yet you believe it is acceptable to plot a race course, or even fly it over glider, or skydiving operations without the operation knowing about it? Ripping across the airspace as fast as you can go not knowing if they know you are there?

Obviously there are many different folks on here with differing ideas of what is acceptable.

As to answering the OP's question. As long as you accept that not getting it restarted, or someone cutting you off in the pattern could result in an extremely embarrassing (at the very least) outcome (to you and or the poor schmuck that you would possibly cut off in the pattern). To me the risk you pose on the other guy makes it not the best of plans.

I used to train twin turboprop students with one engine feathered landings. I don't do that anymore because of incident reports.

Mark

Dealing with an engine failure is a mental issue of dealing with the event. If practicing it serves to prepare for it, have at it, but do so with the knowledge it is not risk free.

When it happens for real, it won't be at a time or place of your choosing. A pre-planned, previously practiced response, is not always be the best response. The circumstances of the failure are not predictable and as such, one needs to hang a bit loose with regard to reacting to the event. It really depends on the airplane and the operation. An engine failure on or immediately after take off requires a different response than one at altitude.

I've shut one down at 10,500' due to a prop failure and another simply quit cold at about 1000' agl. As stated above, both were a surprise. I had never practiced a SEL shut down so it was a first experience. Practicing it would not have mattered, IMHO, you deal with the matter as circumstances dictate. The objective is to land and walk away from it. Bob Hoover once said, fly the airplane as far as possible into the crash - that's what it is all about - do not stall. You do not have to practice not-stalling-an airplane, just fly it normally, push the nose over and keep it flying.

The FAA does not require or recommend training with an engine shut down for good reason, the risk involved is not worth it. Same applies to shutting down an engine with a twin. Too many people have died doing it.

The message here is do not minimize the risk. It is real.

This business of diving to start the engine seems an exercise of going no where but down. Why not use the starter?

David-aviator said:

This business of diving to start the engine seems an exercise of going no where but down. Why not use the starter?

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Well, it's possible the starter is non-functional, so the question is not entirely academic. In many cases though, the answer is "Because I can!" I'd be lying if I said I didn't enjoy pointing the nose down 30 degrees to build the airspeed and spin it up.

Low Pass said:

As for shock cooling, I wouldn't and don't worry (-320, 360, 540 series). What happens when you fly though rain?

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That's not what Lycoming says ... but what do they know... they only designed and built it

David-aviator said:

When it happens for real, it won't be at a time or place of your choosing. A pre-planned, previously practiced response, is not always be the best response. The circumstances of the failure are not predictable and as such, one needs to hang a bit loose with regard to reacting to the event. It really depends on the airplane and the operation. An engine failure on or immediately after take off requires a different response than one at altitude.

Click to expand...

Thanks David, you saved me a lot of typing. In the real world, training never seems to cover what really happened. Too many possible combinations.

A couple of thoughts on stopping engines in flight. First, it is a big, avoidable risk. If you are intent on exploring that part of the envelope I suggest working out some "zero thrust" power settings, just enough to negate the prop drag but not enought to extend the glide. It will take a little time to find the power settings in a particular aircraft. I would suggest having someone else (CFI) handling the power setting while you fly the airplane. This way when the plan doesn't work out, you don't have to explain it at the hearing.

John Clark ATP, CFI
FAAST Team Representative
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA

Pat Stewart said:

To each his own, not my idea of good risk management.

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Agreed...I don't think the idea of shutting off your engine in flight is a safe way to practice engine outs. Why stop a perfectly good running engine and possibly create a problem where there never was one?
I think shock cooling is the least of your worries with this practice. There are more stats of pilots crashing/having incidents with this practice than there is of any benefit one may perceive it provides. I practice engine outs by reducing power to idle. Is it the same as an engine out...no. Is it close enough...yes. Is it safer than shutting down a perfectly good engine in flight...yes. Not trying to be rude here. I am curious as to what your rationale for this practice is?

I think the value of practicing dead stick landings and engine out is imprinting in your mind what it is you want to do, possibly more so than how your plane is going to act when it actually does go toes up.

My guess -- and I hope it remains a guess forever -- is that an engine out is an entirely different beast when you intentionally make it so as opposed to when you're cruising along and all of a sudden it gets really quiet. I'm not sure you can ever really practice that and I'm not entirely sure that fact makes flying the plane the same in that situation. I'm not sure it doesn't either. Like i said, it's just a guess.

But the procedures certainly are the same and if I had to assign a priority on preparing for the worst, getting to the point where the brain automatically takes over in those first few minutes would be -- and is -- job #1.

I'm certainly not going to judge anyone who approaches it differently.

Good luck.

MauiLvrs said:

That's not what Lycoming says ... but what do they know... they only designed and built it

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This. Just read an article about this yesterday, cooling of 50-60 degrees per minute is classified as shock cooling and can do damage to the pistons and rings (assuming the motor is turning). If the motor is stopped though?

Shock cooling can lead to cracked cylinders. The damage is cumulative or cyclic in nature.

Out here, the glider tow pilots use special descent techniques to avoid that, or at least did in the '80s. I had the good fortune to get a brief bit of instruction from a CFI who was an active tow pilot. In a 180 hp Super Cub, the procedure was to keep the power at cruise, roll 90 degrees, use elevator to manage airspeed. When at the desired altitude, roll out and make a normal approach.

Dave

There is no right answer for all people in a question such as this. What some of us do for fun or entertainment (skydiving, scuba, racetracks, etc) would make the more conservative types pop a blood vessel. The 'envelope' that we each push varies in size from individual to individual and some aren't going to push the envelope regardless of how small it is while others will push it regardless of how large it is.

The older we get the more certain we typically are that our way is the only way and that our skillset is as high as the bar can go. My only suggestion is that we all realize that neither of those two statements are remotely true. In my case, I know that most if not all of my friends are better pilots than I am but I learn a lot from them. While I won't be shutting my engine off for quite some time....I fully respect a pilot whose confidence in his equipment and ability tells him its ok. That decision is no more difficult or life threatening than the every day decision on max cross wind to land in. Both can kill you. We make such decisions every time we fly. I say, by all means work within your envelope....but pushing it makes you a better pilot.

Eddie P said:

Once you stop the prop...........,
the gyroscopic precession of the 2G pull up acting 90 degrees to the prop will get the prop to swing just enough for the air to then force the prop to windmill again.

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This is bad physics. If the prop is stopped there is no gyroscope to precess.

Not everyone can take advantage of this twist on it, but for those that live out west, consider doing this over a dry lake bed of known conditions. When we do Alvord Desert campouts, that is part of my morning routine. Get up in the air, do some acro, cool the engine off a bit, then do some dead stick practice. Repeat until you can generally land it between a couple of random marks on the lakebed. Winds are generally calm and the runway below you is only 6x11 miles. Hard to miss it...

It think practicing in this way limits risk (as much as reasonably possible) and gives you some valuable time in a condition we all talk about but rarely can practice safely. One of the lessons for me was to play with the different drag conditions (prop spinning v/s stopped) and to leave my hand off the throttle and fly the airplane all of the way to the surface. A slight amount of extra energy helps arrest the sink rate if you have a spinning C/S prop. Glider pilots probably already have these concepts down, but the rest of us don't have a lot of time in this condition.

http://www.vansairforce.com/community/showthread.php?t=67380

My $.02 worth...

Joe Blank said:

Not everyone can take advantage of this...Alvord Desert... Glider pilots probably already have these concepts down, but the rest of us don't have a lot of time in this condition...

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Since nearly everyone on this forum has a gliderport nearer than an Alvord Desert, why not just go get the glider time? The greatest risk there is that of gaining a valuable boost in one's basic airmanship skills. Who doesn't need that?

A lot of good points here. I know it is not recommended to shut down a perfectly good engine. There is some increased risk for sure. However I did it and wanted to know how the aircraft reacts, how is the restart going and how if the starter or battery is bad.
For me I found out that when my engine doesn´t seize, the prop is windmilling. I can get it stopped only going slower with 20* flaps (or like in areobatic maneouvers). One second of starter assist and the thing is windmilling again. Without the starter I have to dive at 130 KIAS to start the windmilling.
I did this high and reduced power slowly in warm weather not to schock cool the engine, after restart I applied power slowly to avoid local heat buildup. Of course I was close over the field just in case.
I believe that the difference in gliding distance with windmilling engine or not is not that significant, so doing actual deadstick landings with idle power for training purposes is good enough. In a real emergency there is the wind which influences the gliding distance, so judgement here is always necessary.

Pulling the mixture to idle cutoff can be a worthwhile exercise if you have a CS prop. This will tell you if the windmilling prop will still go coarse which will greatly improve your glide ratio.

Fin
9A

Well

I had to reread my post, just to be sure I didn't ask a question about the validity of doing what I did, or if I thought it was safe or not. I asked whether or not there was any harm done to the engine, or will do to the engine from doing this, the only thing I could think of was shock cooling, a risk I thought of before executing this maneuver and took the appropriate precautions, both on shutdown of the engine and on the restart. But is there anything else, engine health wise, that I could be overlooking.

Look guys, as somebody pointed out, there is risk in what we do, like it or not. The day that I refuse to accept the fact that there is some risk behind flying, I quit flying, its that simple. I take more "calculated risks" when I am by myself. Both for education and to ready myself for real world emergencies. Notice I say, by myself. Cause that is the best time for things to go wrong, I want nobody else in the plane.

As a side note for anybody who chimed in who hasn't done this. This was absolutely a great learning lesson. There is a lot to think about before doing this. I learned a lot and have absolutely no regrets about doing it. I am not saying that everybody should run out and do this. But, I have recently started to run a mixture of mogas in my right tank. I tend to burn the mogas exclusively in cruise, sometimes to the point of running that tank dry. Like it or not, the best indicator that the tank is empty is when the engine stops running. Rather than avoid this situation, I have decided to embrace it, and find out what happens, in the most controlled way, without going crazy, I can think of. Is what I do for everybody, absolutely not.

And to whoever said they hope instinct takes over when their engine goes out. I really do hope your instinct just takes over and you do a great job if things hit the fan. Me, I guess I don't trust my instinct all that well, so I'm going to practice, practice, practice. That way when I'm taking young eagles, my nieces, friends, family, strangers, anybody flying, no matter what happens, I can always say "I did my best to be the best I could be, and I'll do my best to keep you safe and make it back." And that's all anybody can ask!

As a side note, Chuck Yeager must be a flippin idiot!

Randy

8A

Only when high

I'd only do this above 12,500 so I could blame oxygen deprivation for my poor judgment.

When my prop stops I want to be able to open the canopy and get out. (On the ground, of course)

The rest of my post was edited because it violated a lot of VAF posting rules.

Jim
RV-4 flying (and prop turning)

SMRacer said:

I'd only do this above 12,500 so I could blame oxygen deprivation for my poor judgment.

When my prop stops I want to be able to open the canopy and get out.

The rest of my post was edited because it violated a lot of VAF posting rules.

Jim
RV-4 flying (and prop turning)

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Holy cow, you'd bail out of a perfectly good airplane cause the engine stopped?

And you had to edit your post, holy cow batman!

Randy
RV8A (prop turning and stopped, cause the airplane don't give a hoot.)

Again to each is own but I have been flying for about 30 years and have done too many go arounds, saw too many deer cross the runway in front of me, had cars cross in front of me, had hot shots in airplanes cut me off on short final and no matter how good I thought I was I have misjudged the approach countless times and had to add power. Although I realize you can reach down and hit the switch and start the engine, I mean hope I can start the engine there just is not enough time to recover if it does not fire immediately. I did like the dry lake bed idea but I am convinced if someone makes this something they do regularly we will be reading about it someday. Yes, I Understand what opinions are worth but we are all trying to promote safety and protect this hobby we all love so much

I just gotta' stick my nose in here. It is just another self launch motor glider. All of the same rules apply.

If you don't have experience in the realm, get some in a training environment, then enjoy the RV motor glider that you never knew you had all along. You'll squeal as you climb the free thermal up to 10k' in your RV in the desert.

Yes, some of the performance numbers are different, you might be surprised that some are the same. But isn't that part of the fun of being a pilot that can adapt to different aircraft? I got my standard .6hrs of fun RV glider time this past weekend and will be ready for another fix soon.

RISK

1-Closed course air racing
2- Aerobatics without proper training
3-Low level aerobatics


Way,way down the list-shutting down the engine on a light single engine airplane and playing glider.
Ways to make it safer-pick a nice long wide runway at a location with very little traffic. Further enhanced by having a useable grass area on at least one side of the runway which you can use in case that unexpected traffic does show up and try to cut you off.
Picking an airport that has no fuel and few based aircraft further lowers the risk.

I did a series of tests with the engine off and learned several things. It was relaxed. It was nothing at all like it is to fly a dedicated glider which is much much easier to land on a spot with precision.

It is not possible to have a zero-thrust power setting with a fixed pitch RV-6. That is one of the things I learned. When the engine is running there is residual thrust in this airplane and deceleration during the flare is more rapid than what one is used to.

Another thing that I learned is that when flying slowly it is not easy to tell if the engine is running or not (in my airplane). I also learned what speed it takes to stop the prop and got a sense of whether it would be worth it for the increased glide (probably not unless very high). I found out that it takes less speed to crank the engine with airflow right after a shut-down than it does after the engine has cooled off some.

I don't recommend these tests to anyone. I did them near a low traffic airport with many landing options. I am very glad I did them for myself and never felt I was doing anything the least bit dangerous.

If I caused some damage to the engine, it has certainly not shown up after about another 1,000 hours. If it does show up I will consider that part of the price of knowing the airplane. Lots of multiengine airplanes have engines shut down every day for training purposes.

Edit:

Upon further reflection, well it would be possible to have zero thrust settings at some particular speeds but not at low speeds.

N208ET said:

Holy cow, you'd bail out of a perfectly good airplane cause the engine stopped?

And you had to edit your post, holy cow batman!

Randy
RV8A (prop turning and stopped, cause the airplane don't give a hoot.)

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Agreed. I fly ejection seat airplanes and would roll the dice with a dead stick over getting out. The F-16 (and every single engine jet I've flown) all have flame out profiles for a very good reason. Getting out is a last resort usually reserved for an airplane that uncontrollable, or injury that renders you unable to fly/land.

Off airport at 50-60 knots is much less risky than a silk ride, depending on terrain.

N208ET said:

I can't really think of any reason why there would be harm to the engine but I thought I would ask if there is anything I should be aware of before doing this again. Maybe shock cooling?

Randy
8A
0-360

Click to expand...

I wouldn't be concerned about shock cooling unless you went from full power, high CGT flight to dead stick quickly.

As far as your tests are concerned, I found that it took 140 knots to spin the wooden prop on my airplane for a restart. The reason I've practiced engine out flight is to verify the airplane's glide ratio and also to see how the airplane performs from over the numbers through the flare without power.

It turns out that my cruise pitched prop generates substantial thrust at idle, so the airplane bleeds energy in the flare much faster with the prop stopped than in a normal landing. A good thing to know if I ever have an engine problem.

Kyle Boatright said:

I wouldn't be concerned about shock cooling ...

Click to expand...

Maybe you could get a job at Lycoming and straighten out their engineers.
I get my information from the factory engine manual. Not sure where you get yours.
Our EMS is set to alert above 40 deg./min.

RE: Lycoming Recommendations

MauiLvrs said:

Maybe you could get a job at Lycoming and straighten out their engineers.
I get my information from the factory engine manual. Not sure where you get yours.
Our EMS is set to alert above 40 deg./min.

Click to expand...

Well, here's one person's opinion of Lycoming's "experts":

Lycoming Rebuttal (Not so much about shock cooling, though)

BobTurner said:

This is bad physics. If the prop is stopped there is no gyroscope to precess.

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Well I'm glad someone thought about the implications of this a little as I never really bought the exact "explanation" either. But what explains the prop turning over under G loading? It's been demo'd to me personally and it is interesting none the less. Cheers-

Oh, another thought Bob let me know what you think... perhaps under G loading, all that is happening is the air flow is changing to a different path (relative wind angle to the aircraft longitudinal axis or alpha) and it might be providing a little extra force / aerodynamic effect to one or both of the prop blades due to prop pitch interaction to the new airflow... to give the prop a bit of extra push to tick it over. And of course once the prop is moving and the initial engine rotational drag is overcome the relative airflow will keep the prop turning turning just like a starter. As I mentioned this CFI demo was in a specific engine/prop/airframe combo.

Those low level self imposed engine outs and simultaneous aerobatics seemed to work just fine for Bob Hoover.

N208ET said:

And to whoever said they hope instinct takes over when their engine goes out. I really do hope your instinct just takes over and you do a great job if things hit the fan. Me, I guess I don't trust my instinct all that well, so I'm going to practice, practice, practice.

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I think that was me and that's not really what I said. It had nothing to do with "hoping." It had to do with practice, practice, practice in whatever way makes one comfortable. We don't disagree. and the methods we choose are not mutually exclusive. It all counts toward the end goal.

MauiLvrs said:

Maybe you could get a job at Lycoming and straighten out their engineers.
I get my information from the factory engine manual. Not sure where you get you.
Our EMS is set to alert above 40 deg./min.

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I love when people I've never met use incomplete or out of context "quote" to get snippy with something I post.

No soup for you!

Safety?

Nihon_Ni said:

I'm firmly in the camp who thinks practicing real emergencies is too much risk for too little reward. Although you may be within gliding distance of your home airport, what happens if the runway fouls when you are on short final or there's some other need to make a go around? If you have the skills to land the airplane with a windmilling prop, then you can apply those same skills to land if the engine ever quits for real.

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I agree with Rob. Every approach simply put is managing power (or lack thereof) and airspeed for current conditions to achieve the desired touchdown in a desired location. So I really don't see the value in simply stopping the engine unless you are considering the emotional thrill of a stopped engine.
I understand that all flying (and everything in life) has a risks factor involved. Aerobatics, night flying, IFR, etc all have their risks....the problem is that you increase the risk factor substantially when you purposely lose the engine so you can play "dead stick" which IMHO gives no benefit to flying skills. It seems to me of more a matter of "beat the odds".....beat the odds that another airplane won't cut you off in the pattern; that someone won't take the runway when you have no time to respond; that some fool on a bicycle decided to stroll along the runway(yup happened to me)....or any other thing you can think of could happen. This isn't a risk that is a byproduct of a realm of flying (eg-aerobatics, IFR, formation etc) it is a created risk that can effect other people.

But then I guess the dumb bike rider, the stupid pilot who pulls out on the runway, or the homeowner who built his house too close to the runway along the final approach course, deserve what happens to them because we had to have the engine totally stopped Hmmmm...maybe we should practice removing the elevator cables/pushtubes to see how it is using the trim tab to try to maintaining pitch.....wow what a rush that would be!

We know there is no regulation against such activity described in this thread, but if something goes awry and there is an accident or incident.....I would about guarantee that FAR 91.13 would be invoked...and the pilot cert be revoked! I think the "shock" wouldn't be in the cylinders.

Skykingbob said:

I agree with Rob. Every approach simply put is managing power (or lack thereof) and airspeed for current conditions to achieve the desired touchdown in a desired location. So I really don't see the value in simply stopping the engine unless you are considering the emotional thrill of a stopped engine.
I understand that all flying (and everything in life) has a risks factor involved. Aerobatics, night flying, IFR, etc all have their risks....the problem is that you increase the risk factor substantially when you purposely lose the engine so you can play "dead stick" which IMHO gives no benefit to flying skills. It seems to me of more a matter of "beat the odds".....beat the odds that another airplane won't cut you off in the pattern; that someone won't take the runway when you have no time to respond; that some fool on a bicycle decided to stroll along the runway(yup happened to me)....or any other thing you can think of could happen. This isn't a risk that is a byproduct of a realm of flying (eg-aerobatics, IFR, formation etc) it is a created risk that can effect other people.

But then I guess the dumb bike rider, the stupid pilot who pulls out on the runway, or the homeowner who built his house too close to the runway along the final approach course, deserve what happens to them because we had to have the engine totally stopped Hmmmm...maybe we should practice removing the elevator cables/pushtubes to see how it is using the trim tab to try to maintaining pitch.....wow what a rush that would be!

We know there is no regulation against such activity described in this thread, but if something goes awry and there is an accident or incident.....I would about guarantee that FAR 91.13 would be invoked...and the pilot cert be revoked! I think the "shock" wouldn't be in the cylinders.

Click to expand...

There was not much "play dead stick" about it. This wasn't a "play" maneuver, it was a "practice" maneuver, which happened at around 830 on a Monday morning, meaning, there wasn't anybody there. At 3K feet down to pattern I was looking all the way down, no radio contact either, had there been any sign of traffic I would of aborted. The entire downwind leg was flown looking for signs of anything on the runway and taxiway. Had their been I would have aborted the maneuver. Along side the main runway, there is a turf runway, on both sides of those, there are the taxiways. The point is there was options if at that point I had been looking and saw something, or decided there was a risk and couldn't get the engine going there was a way out. Increase the risk factor substantially? I'd say I tried to minimize the risk factor as much as possible

There is an increased risk for night flying. Why is that, cause if the engine goes dead, you better hope your over a lighted airport cause if your not, your going to crash into something you can't see, people walking their dog, a kid on his bike, etc etc. Why in the world take the risk, fly during the day. Your odds of being killed in an accident at night are much higher.
EVERYBODY STOP FLYING AT NIGHT RIGHT NOW!!!!! Formation flying, don't even get me started. Aerobatics, your crazy.

I'm not exactly sure why this is that much different from a glider, oh right, the glider has the right of way so everybody will just stay out of his way no matter what. Other than being over something like the Alvord Desert, good idea by the way, this was as controlled as it could be, methodically thought out and executed to the best of my ability. Was there an increase of risk, yup. Was the risk worth the learning reward, YUP! If the engine stopped will I have a good idea of what is going on and what to do, YUP YUP and YUP.

The real crazy thing about this and something I find quite odd, there was a ton to be learned by this, I learn a lot about the way my plane handles, trims out, glides, sounds, feels. Lots of guys seem to see a problem with landing dead stick, most of which have probably never done it themselves, and nobody asked the question of if the landing itself was different. Was anything from the pattern to the ground different, did it change the way my thought process was working or will it change some flying habits that I have had.

And I still haven't heard anything other than shock cooling to watch out for, so it probably isn't too hard on the engine.

I am interested in the 2G pull to get the prop to start windmilling. I have a 3blade catto so I am not sure that would be much benefit to me. If it would be "than it sure would be nice to know before I needed to use it!"

Randy
8A

All Knowledge is good Knowledge!!!!!

... I will chime in here with my experience on this and perhaps someone my get some use out of my findings. I do this propeller stopping scenario quite often and actually find it very relaxing, similar to a sailplane experience. I have done this several times with every airplane I have owned and re-perform the tests with any major change like propeller Etc. perhaps 100 or more times over the years. The propeller has a very dramatic effect on everything and for me I derive comfort from knowing those effects. I don't profess that anyone do this if they are not comfortable with it, or feel they are lacking in required skill level to effect a safe landing Etc. My airplane is a 9-A with a Wherl-Wind RV 200 C/S derivative (very close) propeller. The hub is the none aerobatic like the standard RV-200. This propeller acts very different from most others I have tried and is worthy of some discussion. I will try to keep this as short as possible so I won't elaborate to much. The first thing you will notice is because of its light weight and very little inertia it stops with no effort. Pull the mixture with it in course pitch below 70 Kts. and it stops. Most other props as in F/P you need to make a conscious effort and get almost to stall speed before it stops. Next test was the speed required to restart via wind, That turned out to be 170 Kts. The engine will start to turn over one stroke at a time with a pause in between from 95 Kts. on but requires far more speed to actually establish a full cycle to restart (no flywheel action). Now I moved on to see what and trim to the lowest sink rate I could achieve, full course pitch, idle stop mixture pulled, 650 fpm @ 100 mph. 13.53 to 1 glide ratio, not bad! Next I pulled the nose up, slowed and let the prop stop without changing the trim (should glide better?) nope! It actually got considerably worse @ 12.6 to 1 glide. Took me a bit to figure it out and this came as a surprise to me. When the prop stops the oil pressure goes away and the hub returns to fine pitch This is actually a dirtier configuration than allowing it to windmill in course pitch. Given the option, with this prop, let it windmill. This is the type of information that is good to know. I feel you will have a far better chance of making an informed decision should the need arise, if you are armed with as much information as possible. Thanks, Allan...

Thanks Allan, That is actually great information to know. Prior to reading your post I would have attempted to stop the prop in a long glide on my RV6 with a WW prop. After reading what you posted I will leave it windmilling and concentrate on flying the aircraft. Thanks very much for posting.

George

N208ET said:

There was not much "play dead stick" about it. This wasn't a "play" maneuver, it was a "practice" maneuver, which happened at around 830 on a Monday morning, meaning, there wasn't anybody there. At 3K feet down to pattern I was looking all the way down, no radio contact either, had there been any sign of traffic I would of aborted. The entire downwind leg was flown looking for signs of anything on the runway and taxiway. Had their been I would have aborted the maneuver. Along side the main runway, there is a turf runway, on both sides of those, there are the taxiways. The point is there was options if at that point I had been looking and saw something, or decided there was a risk and couldn't get the engine going there was a way out. Increase the risk factor substantially? I'd say I tried to minimize the risk factor as much as possible

There is an increased risk for night flying. Why is that, cause if the engine goes dead, you better hope your over a lighted airport cause if your not, your going to crash into something you can't see, people walking their dog, a kid on his bike, etc etc. Why in the world take the risk, fly during the day. Your odds of being killed in an accident at night are much higher.
EVERYBODY STOP FLYING AT NIGHT RIGHT NOW!!!!! Formation flying, don't even get me started. Aerobatics, your crazy.

I'm not exactly sure why this is that much different from a glider, oh right, the glider has the right of way so everybody will just stay out of his way no matter what. Other than being over something like the Alvord Desert, good idea by the way, this was as controlled as it could be, methodically thought out and executed to the best of my ability. Was there an increase of risk, yup. Was the risk worth the learning reward, YUP! If the engine stopped will I have a good idea of what is going on and what to do, YUP YUP and YUP.

The real crazy thing about this and something I find quite odd, there was a ton to be learned by this, I learn a lot about the way my plane handles, trims out, glides, sounds, feels. Lots of guys seem to see a problem with landing dead stick, most of which have probably never done it themselves, and nobody asked the question of if the landing itself was different. Was anything from the pattern to the ground different, did it change the way my thought process was working or will it change some flying habits that I have had.

And I still haven't heard anything other than shock cooling to watch out for, so it probably isn't too hard on the engine.

I am interested in the 2G pull to get the prop to start windmilling. I have a 3blade catto so I am not sure that would be much benefit to me. If it would be "than it sure would be nice to know before I needed to use it!"

Randy
8A

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Hi Randy,

I know how you feel.... I posted about this a few years back when I tried it in my 9A and got similar treatment.

I said then and I still believe "An ounce of prevention is worth a pound of cure. Definition: A little precaution before a crisis occurs is preferable to a lot of fixing up afterward."

Pretty sure my engine shouldn't even be running anymore according to a few people back then. (note those posts are gone from the thread now) I now have 1220 hours on it in 339A and the engine has 2000 hours total. Time for a rebuild.... well maybe not, according to Mike Busch. This from an H2AD which is supposed to explode when installed in an RV.

Anyway, welcome to the RV Glider group.

Regards,

339A said:

Hi Randy,
I said then and I still believe "An ounce of prevention is worth a pound of cure. Definition: A little precaution before a crisis occurs is preferable to a lot of fixing up afterward."
Regards,

Click to expand...

But not true if the "little precaution" leads to more fixing up than the crisis it was intended to train for! For example, the FAA won't allow its multiengine examiners to have applicants do real one engine off landings. Too many accidents, with too little gained compared to one engine at zero thrust. In their opinion. They used the same rationale (one I disagree with) to eliminate private pilot spin training.

The issue here is this: Is the extra realism gained by gliding engine off, as opposed to idle, worth the extra risk (runway incursion, can't make the field, engine won't restart, bounced landing, ....)? I am in favor of engine at idle training at light and heavy weights, tailwinds and headwinds. But my personal line stops before turning the engine off.

I think if you are really honest with yourself you would have to say that, really, safety is an excuse here for challenging yourself and having fun. That's not necessarily wrong, as long as we're honest with ourselves about risk.

PerfTech said:

...Next I pulled the nose up, slowed and let the prop stop without changing the trim...

Click to expand...

Just curious: Why not change the trim? You're trying to maximize glide ratio, right?

For a constant-speed prop that you can get into coarse pitch, there's probably less benefit to stopping the prop. But for a fixed-pitch windmilling prop, the drag is comparable to having a circle of plywood, the diameter of your prop, mounted on the hub. A stopped prop, in contrast, has the drag of just the two blades.

In my fixed-pitch RV, if i'm in an unfamiliar area where i'm going to want time to pick the best spot to ditch, or feel that i'd need more gliding distance from altitude, I would stop the prop rather than leave it windmilling.

OK an exercise in logic and statistics:

Scenario 1: You have an engine failure. You have practiced dead-stick landings with the engine running. You know the approach is going to be steeper and make adjustments. You get it right and land safely or you get it wrong and land short with possible damage/injury.

Scenario 2: You deliberately shut down the engine. You have practiced dead-stick landings with the engine running. You know the approach is going to be steeper and make adjustments. You get it right and land safely or you get it wrong and land short with possible damage/injury.

I see no difference between the 2 except that in the second case you have given yourself a 100% chance of an engine failure. I accept that if it is going wrong then you MAY be able to re-start the engine but it doesn't strike me as a good bet to make.

The world is littered with aircraft that crashed doing 2 engine inop approaches or similar high-risk practice emergencies. That's why such manoeuvres have been assigned to the waste-bin (sorry, trash-can) or the simulator.

When I was in the military we had an expression - "practice bleeding"......