Killing engine in flight

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Mtns2Skies said:
what part of the engine in a 172 checks the certification process before deciding to restart?
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The same part that checks that it’s in flight.
 
Lindberg said:
You haven't practiced spin avoidance/recovery, and departure stalls?

No one's saying shut off the engine at 500 feet.
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Half fast covered the 500 foot part. As for your question, yes, I've done countless departure stalls, engine running, power off stalls, engine running, spin avoidance, recovery from incipient spin and recovery after about 6 turns in spins, all with the engine running. All with valuable things learned.

I see nothing useful learned from turning off the engine in a single engine plane, zip.
 
Llewtrah381 said:
While I get your point, it’s equally fair to say a partial loss of power (down to idle power) is also an emergency yet we practice that often.

I personally think there’s merit in doing this, under the right circumstances. For example, it seems good for a CFI to intentionally do it once with a student, planned, at altitude and near a good runway, to show them early on that the plane won’t fall out of the sky if the engine quits; it would better prepare them for such a situation by reducing the panic, IMHO. I could also see doing it with a spouse (if they’re willing!) for the same reason.

And while others have talked about shutting off a fuel valve, I personally hesitate to do that. That introduces another variable/failure mode that doesn’t add benefit, in my opinion.

Also, I personally pull it to idle first. I’m sure it’s probably safe to pull the mixture back while at full power but I just don’t want to add stress to the engine. That said, I could imagine it’s a good lesson to see how the plane behaves going from full power to nothing in a heartbeat. I just opt not to do that.

I’ve also done it just with the mixture: turning the ignition off is not wise, in my mind, for several reasons: a new failure mode and raw gas getting into the exhaust being the main two.
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Pulling the mixture or turning off the fuel, for a carbureted engine will not stress it at any power setting. As the fuel level goes down in the bowl, the engine gets leaner and automatically reduces power before it gets too lean to run.

But what happens if the mixture control gets stuck? Or comes off the carb?

Remember the main rule of flying. Don't do anything that will sound stupid in the NTSB report. Shutting down the engine and not being able to restart is one of those things.
 
Pinecone said:
Pulling the mixture or turning off the fuel, for a carbureted engine will not stress it at any power setting. As the fuel level goes down in the bowl, the engine gets leaner and automatically reduces power before it gets too lean to run.

But what happens if the mixture control gets stuck? Or comes off the carb?

Remember the main rule of flying. Don't do anything that will sound stupid in the NTSB report. Shutting down the engine and not being able to restart is one of those things.
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That's not my main rule of flying. In fact, it's not even in my book.
 
Is there a list of accidents caused by the pilot's decision to shut down the engine in flight? I can't think of any.

If something is physically broken, like a stuck mixture cable which several posters have mentioned above, I'm already in trouble. Leaned for my typical cruise flight at, say, 10,000 feet (in my normally aspirated Bonanza), my engine will get rough in the descent and eventually stop making power if I don't (or can't) enrichen the mixture.

The biggest issue I see with pulling the mixture to idle in flight is that on a cool day the engine will get cold in a hurry. An engine windmilling at 2,500 RPM with cold oil is not a good thing.

On a hot summer day, pulling the mixture to idle can be a great way to demonstrate that the airplane doesn't fall out of the sky when the engine quits. Too many people believe that.

- Martin
 
1) Hint - motor GLIDER.

2) If you shut one down in a multi, you still have one running. In a single, not so.
 
Pinecone said:
1) Hint - motor GLIDER.

2) If you shut one down in a multi, you still have one running. In a single, not so.
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Hint - gliders can land safely on runways.
Hint - planes with an engine out are gliders.
Hint - how many times have you heard about someone not being able to start up the second engine? Out of the thousands of times they are shut down every year.
 
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I shut the engine down in-flight all the time.

/In a Pipistrel motorglider
//Rotax powered
///full feathering

Glider?? I barely knew her:
Nauga, probably
 
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Value of killing the engine in flight?
Glide distance and descent rate with power at idle (simulated engine failure or power off landing practise), versus dead engine and wind milling prop.

Kept her high on base to final and aimed to touch down at the 1200 feet mark. (Roughly the start of the 2nd third of the runway). Trimmed for 70 kts. On short final: pulled the mixture. She shuddered like crazy and then wind-milled.
The bottom fell out. Kept the nose down for 70 kts. Made the threshold and had the energy to flare and touch down.
Light bulb moment. Your thingy does not glide as well as with idle power. Better aim to land long, if really up the creek with a dead engine.

Yes, I ran a tank dry on purpose, once. Low wing. No big deal for some, but it got my heat rate up.

Value. Exactly how long it takes the engine to fire up after switching tanks and switching fuel pump on.
4 seconds in this aircraft.
Good to know what to expect if inadvertently ran a tank dry. (like Adenosine in atrial flutter. Flat line, a screen width! :) )
 
21541803 said:
Value of killing the engine in flight?
Glide distance and descent rate with power at idle (simulated engine failure or power off landing practise), versus dead engine and wind milling prop.

Kept her high on base to final and aimed to touch down at the 1200 feet mark. (Roughly the start of the 2nd third of the runway). Trimmed for 70 kts. On short final: pulled the mixture. She shuddered like crazy and then wind-milled.
The bottom fell out. Kept the nose down for 70 kts. Made the threshold and had the energy to flare and touch down.
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Yeah, I guess there would be some value in demonstrating that when you think you’re making your pattern within gliding distance of the runway, you’re most likely not.
 
Mongoose Aviator said:
The ACS does not state to actually turn off one of the engines during a Multi checkride with a DPE. The ACS speaks of simulated feathering and zero-thrust during the checkride.

I know the DPE during my checkride specifically discussed with me the training I had received with my MEI in regards to actually stopping, feathering and re-starting the engine during flight however the DPE during the checkride appeared to follow the ACS and use the zero-thrust approach while I demonstrated the various single engine maneuvers.
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interesting... I stopped reading ACS when checking this when I read the below....

Aircraft Requirements & Limitations14 CFR part 61, section 61.45 prescribes the required aircraft and equipment for a practical test. The regulation states the minimum aircraft registration and airworthiness requirements as well as the minimum equipment requirements, to include the minimum required controls. Multiengine practical tests require normal engine shutdowns and restarts in the air, to include propeller feathering and unfeathering. The Airplane Flight Manual (AFM) must not prohibit these procedures, but low power settings for cooling periods prior to the actual shutdown in accordance with the AFM are acceptable and encouraged. Fora type rating in an airplane not certificated with inflight unfeathering capability, a simulated powerplant failure is acceptable
 
21541803 said:
snip........ (like Adenosine in atrial flutter. Flat line, a screen width! :) )
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That gave me a good laugh. I call that maneuver "Fun with Interns". Induces a bit of tachycardia in the young 'uns while the vet R.N.'s get a good laugh also.
 
Dana said:
Should've had a poll.

I used to do it fairly often in my T-Craft and unlike Trevor Jacob, my airplane didn't die.

The first time I tried it I was over a long runway with no other traffic in the area, and plenty of grass alongside the runway in case it was obstructed. On other occasions it was above open farm country with plenty of landing options. It had to be slowed nearly to stall to stop the prop windmilling, and yes, glide is noticeably better with it stopped vs. windmilling (prop stopped glide is similar to engine idling). Had to dive near to Vne to get it turning again (the T-Craft had no starter).

Never had a problem getting it restarted; a windmilling prop spins a lot faster than the starter will spin it, and unlike a starter which can crank for only a limited time, it keeps on spinning until it starts. Sometimes I would leave it stopped all the way to landing (control in the flare is noticeably different).

On a couple of occasions on thermic days I actually gained a couple of thousand feet before losing the lift. Fun!

For those of you furiously genuflecting and saying, "BAD! Don't do that!", you're probably right, YOU shouldn't try it, at least not on your own. But some of us have a more inquisitive mind and like knowing how the aircraft performs in all flight regimes.
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And how much different is it doing in in a T-Craft vs a TG-6, depending on you T-Craft it might have even still had the Spoilers.
Of a J-3 vs a TG-8
 
We did this in a PIpistrel motor glider all the time with a Rotax, but you could feather the prop. Granted it's a glider so you have more time but if you needed to relight you had the same pucer "would it start" but it always did.
 
My instructor did as Dan Thomas' instructor did, but when the starter was called for, nothing happened. He and the student landed in a pasture, Federal land.

The instructor got out, hand propped the engine, and they flew out, and home.

That was the last time he did that with his students, and he strongly advised me not to try that, either. One of the many things he told me to avoid that I have taken his advise, as learning form other peoples mistakes is cheaper than doing it myself.
 
mandm said:
I’ve heard that whether the engine is windmilling or stopped it’s pretty similar, no idea how accurate that is.

Also I have read that you should give the engine some short bursts of power while doing power off / gliding to avoid shock cooling the engine.

There are different ways to start the engine, whether it’s a cold start, hot start, etc. So you’ll want to have all of those procedures memorized and mastered.
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My Mooney is rated for a 10:1 glide ratio- gear up, prop windmilling. It’s also rated for a 12:1 glide ratio if the gear is up and prop is stopped…

I had wondered the same thing myself, when I got the Mooney and seen that- they must have tested to calculate that out, so looks like there’s something to it.

BUT being we don’t typically, and I don’t think I would, practice that, I think a pilots really gotta pre-think when they would try that. I think I’d go w the 10:1 and not be trying something like that in a high stress situation, it’s adding a lot of risk, ya botch it n spin, ya do it ok but not brisk enough n loose a lot of alt, etc… others may make a different call…
 
brcase said:
And how much different is it doing in in a T-Craft vs a TG-6, depending on you T-Craft it might have even still had the Spoilers.
Of a J-3 vs a TG-8
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No spoilers on a B model T-Craft like mine, only the L-2... though the FAA wants them wired shut on the L-2s nowadays.

I imagine the glider versions had less drag than their powered cousins, so the spoilers would have been nice to have to counter the typical T-Craft float.

(For those unfamiliar, the TG-6 and -8 were training gliders of the L-2 and J-3... remove the engine and add a third seat.)
 
Salty said:
I’ve intentionally shut down an engine once. I felt it was important to know just how much difference there is in an idle engine vs shut down. I got a lot of crap here for doing it. I did it directly above a runway. I still think it was worth the risk to do it once, but I don’t feel the need to ever do it again, and I wouldn’t treat a 172 like a glider.

Here’s the thread if you want to read. https://www.pilotsofamerica.com/com...dmilling-the-truth.132499/page-2#post-3133239
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I've done it once, for the same reason.

I've also run tanks dry...I've also made approaches to landing intentionally leaving the gear up all the way through go around (maybe getting to a little less than 200 feet AGL)...same reasons: for knowledge and experience.

If you've never done it even once, then you might be completely caught off guard if you should encounter the situation again, that time unintentionally.
 
Dana said:
No spoilers on a B model T-Craft like mine, only the L-2... though the FAA wants them wired shut on the L-2s nowadays.

I imagine the glider versions had less drag than their powered cousins, so the spoilers would have been nice to have to counter the typical T-Craft float.

(For those unfamiliar, the TG-6 and -8 were training gliders of the L-2 and J-3... remove the engine and add a third seat.)
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I never quite figured out why the FAA doesn’t like operational spoilers on the L-2…I found them very handy and usable.
 
Gilbert Buettner said:
When it happened to me and my crew, we were 200 miles east of Langley out over the Atlantic. We still had three. <g>
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Amateurs....my one and only flight in a B52 (not yet approved to go back into service after overhauls so I got a ride as a civ contractor) the pilot shut down one engine....didn't even notice unless you looked at the instruments.

Oh Gosh! The Dreaded Seven Engine Emergency!
 
MauleSkinner said:
I never quite figured out why the FAA doesn’t like operational spoilers on the L-2…I found them very handy and usable.
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Most likely because of the marginal rate of climb with spoilers deployed... the same reason the C-152 has only 30° of flaps when the 150 had 40°. A full flap go-around in a 150 could be exciting in the wrong way.
 
Gilbert Buettner said:
When it happened to me and my crew, we were 200 miles east of Langley out over the Atlantic. We still had three. <g>
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I know the USCG routinely shut down two in flight to reduce fuel consumption.

But they still had 2 running, which was enought to keep flying. But they do fly them fairly light.
 
Pinecone said:
I know the USCG routinely shut down two in flight to reduce fuel consumption.

But they still had 2 running, which was enought to keep flying. But they do fly them fairly light.
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We were heavy for the ocean crossing and immediately lost altitude with one shut down. Turned out to be a fault in the fire warning system. The engine was ruined by shooting two fire extinguisher bottles into it.
 
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