Engine about to die, minutes of power left, what to do?

[Thunderbird83]

The story of the Cirrus ditching in the Bahamas last week got me thinking... In his case, he knew the situation was critical. Oil pressure had fallen, and it was only a matter of time before the engine stopped revolving. He was over the ocean, cruising at 8000' and the closest airport was still 25 miles away.

If you know your engine is about to eat it, but you are still generating enough power to maintain level flight or climb, what is the best strategy to extend your range? '

I see a couple of options while still making power and aiming towards the closest airport.

1: Sacrifice airspeed (and distance) for altitude. Climb as high as possible (at Vy?) and prepare to establish best glide speed when the engine quits. You wouldn't have traveled as far when the engine dies, but you'll be able to glide longer. Will that extended glide make up for the distance sacrificed in the climb?

2: Maintain level flight at max forward speed. You'll travel further before the engine quits, but you won't be able to glide as long.

3: Other options? Reduce power to potentially extend the life of the engine?

What sayeth you peanut gallery? Save my life.

 

[EdFred]

Vmindrag

 

[dmspilot]

Can't remember where I read it, but the engine will run much longer before seizing with no oil pressure while flying at best glide. More than enough to offset the slower speed.

 

[Huckster79]

IDK why in detail, but my gut would tell me to hold altitude at most, laboring an engine that is dying just doesn't hit me as the right thing to do. Though that is my gut not expertise...

 

[JonH]

Maintain flight level and look for something closer while troubleshooting and preparing to ditch.

 

[AKBill]

In my case flying SE AK. Land on the best beach you can find without boulders the size as a VW...

 

[Salty]

Whatever best glide / Vy results in. It will be a climb if you’re producing enough power, or slow the descent if not, but best glide will take you the farthest, even while the engine is running you’ll get the best distance possible out of the energy left.

 

[Checkout_my_Six]

Carson speed forward (1.3 x Vso).....and hope for the best.

but....thinking more on this....It might not be just about minimizing drag. "Time" might be important too. With no oil pressure the engine seizing will be a function of RPMs which is time based. So, I might go for that which gets me there the fastest.....which might not make much of a difference.

 

[Salty]

Carson speed forward (1.3 x Vso).....and hope for the best.

but....thinking more on this....It might not be just about minimizing drag. "Time" might be important too. With no oil pressure the engine seizing will be a function of RPMs which is time based. So, I might go for that which gets me there the fastest.....which might not make much of a difference.

I’m still thinking you have x rotations left, best glide is going to get you the farthest on those rotations.

 

[GMascelli]

Pitch for best glide, pick your spot and FLY THE PLANE.

 

[eman1200]

I didn't think cirrus pilots were taught anything other than 'pull the chute'. you're asking them to 'think' like a 'pilot'?

 

[Kenny Phillips]

I didn't think cirrus pilots were taught anything other than 'pull the chute'. you're asking them to 'think' like a 'pilot'?

Actually, they are taught to "pull the chute" in many situations, but that final decision is up to the PIC. If I had ten minutes to think about it, I may try to land somewhere.

 

[Skip Miller]

Don't try to prolong the inevitable! If you see a really good place to land off airport, take it! Alaska, for example, (AK Bill, I am not picking on you) has many thousands of square miles where forced landing survival is doubtful at best. Communicate your intentions and land.

You do have survival equipment aboard, right?

-Skip

 

[Brad Z]

Generally speaking, pitch for best glide, regardless of the power output, and treat it the same way you'd handle an engine out (which eventually it will be). Point in the direction of where you'd like to land, consider winds, vessel traffic, etc. And declare your emergency. For ditching, try to do it near a boat or vessel and make sure they can see you from the bridge--close enough that they can see you but not so close that they run over you or swamp you with their wake.

 

[AKBill]

Don't try to prolong the inevitable! If you see a really good place to land off airport, take it! Alaska, for example, (AK Bill, I am not picking on you) has many thousands of square miles where forced landing survival is doubtful at best. Communicate your intentions and land.

You do have survival equipment aboard, right?

-Skip

I do carry survival equipment. On a lot of flights I wear an inflatable vest. One of the things that bugs me is egress. If I'm in the water not a whole lot of time to grab the survival gear, if I'm in the water upside down even less time.

 

[Huckster79]

The trim for best glide case makes a lot of sense.... And be ready for the PUSH when she conks, as attitude will need to change fast, like power loss on climb out... I also agree if there is a spot to put her down safely don't bypass it!!! It would be foolish to fly past a hayfield to hope to get over 25miles of forest or whatnot...

 

[jsstevens]

The trim for best glide case makes a lot of sense.... And be ready for the PUSH when she conks, as attitude will need to change fast, like power loss on climb out... I also agree if there is a spot to put her down safely don't bypass it!!! It would be foolish to fly past a hayfield to hope to get over 25miles of forest or whatnot...

If you re trimmed for best glide, you do not need to push. The airplane will seek the trimmed airspeed on its own. If you're holding a pitch angle to maintain that speed, then be prepared to relax the pull (or even push). But if you're trimmed, no need. Next time you're flying, try it at altitude. Trim for best glide with cruise power. Once it's stable (it'll be climbing), pull the throttle (don't forget carb heat if so equipped) and see what the plane does. It'll nose over to maintain best glide speed. You can do it hands off assuming your plane is stable in roll.

 

[WannFly]

 

[Van Johnston]

If I know the engine is going to go, no matter what, and it is just a matter of time but I don’t know the time ... the engineer in me says my total energy is composed of potential energy (altitude), kinetic energy (airspeed),and chemical energy (fuel). Once the engine goes, I can no longer convert the chemical energy into potential or kinetic energy, so I need to take advantage of that while I can. So my answer is climb at Vy, as long as possible, then max forward speed as long as engine lasts.

 

[RyanShort1]

If you know your engine is about to eat it, but you are still generating enough power to maintain level flight or climb, what is the best strategy to extend your range? '

I see a couple of options while still making power and aiming towards the closest airport.

1: Sacrifice airspeed (and distance) for altitude. Climb as high as possible (at Vy?) and prepare to establish best glide speed when the engine quits. You wouldn't have traveled as far when the engine dies, but you'll be able to glide longer. Will that extended glide make up for the distance sacrificed in the climb?

Terrain matters. Over water - point towards the best combination of towards land - towards a shipping lane - towards a ship you can see that might help rescue you. Over land - if you're over suitable landing area, put it down right away, if not, head towards whatever looks best.

2: Maintain level flight at max forward speed. You'll travel further before the engine quits, but you won't be able to glide as long.

I'd maintain exactly whatever I currently had in level flight with as little drag as possible

3: Other options? Reduce power to potentially extend the life of the engine?

I've been told by smarter folks than myself that when you have an engine issue where it's running, but likely to stop, do not CHANGE anything unless you are pulling power to land. You change something inside the engine, you induce the potential for earlier failure.

 

[Huckster79]

If you re trimmed for best glide, you do not need to push. The airplane will seek the trimmed airspeed on its own. If you're holding a pitch angle to maintain that speed, then be prepared to relax the pull (or even push). But if you're trimmed, no need. Next time you're flying, try it at altitude. Trim for best glide with cruise power. Once it's stable (it'll be climbing), pull the throttle (don't forget carb heat if so equipped) and see what the plane does. It'll nose over to maintain best glide speed. You can do it hands off assuming your plane is stable in roll.

I most definitely will give that a whirl! So in theory if our plane always Had the same weight and balance we could mark our trim wheel with air speeds?

Darn it! Now you gave me a reason I “have” to go fly! Lol

 

[Huckster79]

I'd maintain exactly whatever I currently had in level flight with as little drag as possible

I've been told by smarter folks than myself that when you have an engine issue where it's running, but likely to stop, do not CHANGE anything unless you are pulling power to land. You change something inside the engine, you induce the potential for earlier failure.

I’ve been told the same thing. Let her be inputwise, at least if it were oil pressure or whatnot... if it was just running rough for unknown reason I’d definitely try carb heat, mixture, etc.. definetly carb heat on my c85 icemaker...

 

[Ravioli]

Climb until your airspeed decays to best glide and then pitch to keep best glide. Those few hundred extra feet could be the game changer.

 

[Huckster79]

If I know the engine is going to go, no matter what, and it is just a matter of time but I don’t know the time ... the engineer in me says my total energy is composed of potential energy (altitude), kinetic energy (airspeed),and chemical energy (fuel). Once the engine goes, I can no longer convert the chemical energy into potential or kinetic energy, so I need to take advantage of that while I can. So my answer is climb at Vy, as long as possible, then max forward speed as long as engine lasts.

This would be an interesting theory to test in terms of distance made. Set up at altitude, do your method of climb a given amount pull power and see how far the glide went.

Then do the same but maintain altitude for same time you climbed pull power and see glide distance.

The unknown variables though would be: in real life situation we wouldn’t know how long the climb would be, and would the load of climb bring her demise earlier. Which leads me to wonder if a shallow decent, depending on terrain, may take some load/heat off the engine extending its inevitable demise. Any engine experts to chime in on climbing with a dying motor?

We just had a 172 put down on a road at my neighboring airport- lost oil pressure couldn’t keep her going and ducked under a stop light n put it down without a ding...

 

[Tantalum]

It depends where I am
-over water or inhospitable terrain?
F the engine.. let her keep making power until it seizes.. pitch for Vg.. and start calling for help.. 121.5 all the way home

-over some place else?
try to land if I can.. on a typical flight from MYF up to pretty much anywhere south of SBP you can be on the ground, at an airport.. generally within about 10 minutes.. so point to the nearest airport and if the engine quits then Vg it and pull the chute at 1K AGL. 9/10 times I'll be pulling the chute should the engine quit before I can get it on the ground. The Cirrus gets VERY draggy with flaps in.. and stays very fast without. So short of staring down the runways at LAX or Miramar or Vandenberg I'm pulling the Jesus Handle

 

[Zeldman]

Engine about to die, minutes of power left, what to do?

I would call my cousin, Roy.

Because he ain't never seen no airplane crash like the one we're gonna have......

 

[jsstevens]

I most definitely will give that a whirl! So in theory if our plane always Had the same weight and balance we could mark our trim wheel with air speeds?

Darn it! Now you gave me a reason I “have” to go fly! Lol

Yes! Get out there and test one for the team! Go! Go! Go!

I was taught (pretty sure in primary but I know we used it in IR) that the airplane will pitch to seek the trimmed airspeed. In the 172, 200RPM reduction will give you darn near a 500 FPM descent rate (clean) every time.

 

[James331]

Fly to your target and pitch for best glide and (be it going up or down), also remember best glide chances with weight, this is one of the areas a AOA is a nice tool to have. I’d also not make any changes to the engine settings for the most part till you are runway assured or it checks out.

 

[Radar Contact]

What sayeth you peanut gallery? Save my life.

Shutdown/Feather it and truck on.

 

[Clip4]

I think I would continues and be searching the surface for a boat.

 

[Huckster79]

It depends where I am
-over water or inhospitable terrain?
F the engine.. let her keep making power until it seizes.. pitch for Vg.. and start calling for help.. 121.5 all the way home

-over some place else?
try to land if I can.. on a typical flight from MYF up to pretty much anywhere south of SBP you can be on the ground, at an airport.. generally within about 10 minutes.. so point to the nearest airport and if the engine quits then Vg it and pull the chute at 1K AGL. 9/10 times I'll be pulling the chute should the engine quit before I can get it on the ground. The Cirrus gets VERY draggy with flaps in.. and stays very fast without. So short of staring down the runways at LAX or Miramar or Vandenberg I'm pulling the Jesus Handle

Curious, not cantankerous; would you pull the handle engine out with hayfield/frozen lake (if we didn’t have tons of snow), nice par 4, etc available?

I certainly get it at night, over inhospitable terrain, etc... but idk if I would if I had a suitable landing spot... just seems like there’s still danger involved, clipping a tall tree, ect- that I could avoid gliding to a suitable landing area. Then again I’m not faced with the conundrum as the ‘47 wasn’t outfitted with that option

 

[Tantalum]

Curious, not cantankerous; would you pull the handle engine out with hayfield/frozen lake (if we didn’t have tons of snow), nice par 4, etc available?

It's a worthwhile question. There was a similar thread about this on the Cirrus forum, and the overall opinion was to pull the chute. Most fields and natural frozen lakes aren't going to be that smooth, and you're still going to be landing going at least 60 knots if not greater.. that's a lot of energy to dissipate. you will most likely be damaging the airplane anyway even if it's just the landing gear. And that's assuming you nailed the pattern and approach perfectly the first time you're ever doing a no engine landing in a plane that gets very draggy with full flaps or very fast without.. might as well glad yourself to a good area and then pull the chute

outfitted with that option

Nope! But you did have four times as many engines!

 

[Huckster79]

Nope! But you did have four times as many engines!

I meant my 1947

 

[FormerHangie]

If an engine is in the process of failing, you don't know how much longer it will remain operating. As a general rule, if you greatly reduce power, it may continue to run for quite a while. Reduce power a lot, to where you're maintaining altitude but at a low airspeed. Declare an emergency and head for the nearest airport, you may just make it.

 

[flyingcheesehead]

Can't remember where I read it, but the engine will run much longer before seizing with no oil pressure while flying at best glide. More than enough to offset the slower speed.

I would think that, if you still have *partial* pressure, higher RPM would keep higher pressure, but depending on the reason pressure is dropping, you might go to zero faster.

I think you're right that once there is *no* oil pressure, you might be able to keep the engine running for a minute longer if you reduce power, but I don't think you'll really get it stabilized at best glide - I bet it'll seize in a minute. @Ted DuPuis might know?

IDK why in detail, but my gut would tell me to hold altitude at most, laboring an engine that is dying just doesn't hit me as the right thing to do. Though that is my gut not expertise...

It probably depends what the problem is, but I think in general you'd be correct.

Whatever best glide / Vy results in. It will be a climb if you’re producing enough power, or slow the descent if not, but best glide will take you the farthest, even while the engine is running you’ll get the best distance possible out of the energy left.

Yes! And I'm going to hopefully do some math and prove you right.

but....thinking more on this....It might not be just about minimizing drag. "Time" might be important too. With no oil pressure the engine seizing will be a function of RPMs which is time based. So, I might go for that which gets me there the fastest.....which might not make much of a difference.

Might be % power based to some extent as well. If it's strictly RPM based, I'm gonna shove the throttle all the way in and pull the prop back to something fairly low to get as much power out of those RPMs as I can...

If you re trimmed for best glide, you do not need to push. The airplane will seek the trimmed airspeed on its own.

I think it depends on the airplane. Some planes are very sensitive to how the propwash hits the wing and the tail.

It can also be a psychological thing. Pull means up, right? So a pilot losing power shortly after takeoff will tend to pull, so you need to *think* "push" just to cancel out your subconscious desire to pull.

If I know the engine is going to go, no matter what, and it is just a matter of time but I don’t know the time ... the engineer in me says my total energy is composed of potential energy (altitude), kinetic energy (airspeed),and chemical energy (fuel). Once the engine goes, I can no longer convert the chemical energy into potential or kinetic energy, so I need to take advantage of that while I can. So my answer is climb at Vy, as long as possible, then max forward speed as long as engine lasts.

I agree with your thinking, but I'm not sure what your last sentence means? Climb at Vy until you don't have enough power left to continue climbing, then max forward speed (which is still Vy at that point) until you're down to Vg or something? I think @Salty is probably right that Vg regardless is the best way to convert as much chemical energy to kinetic+potential as possible. Probably still aircraft type dependent to some extent.

Terrain matters. Over water - point towards the best combination of towards land - towards a shipping lane - towards a ship you can see that might help rescue you. Over land - if you're over suitable landing area, put it down right away, if not, head towards whatever looks best.

What if you're over a suitable landing area, but there's an airport nearby and you'll be able to glide to either the suitable landing area or to the airport for the entire time you're flying toward the airport? I'd maintain altitude to the extent possible and head for the airport.

I'd maintain exactly whatever I currently had in level flight with as little drag as possible

As little drag as possible = slowing to Vg so as not to unnecessarily lose energy to parasitic drag, in my mind. That means at least a momentary climb.

I've been told by smarter folks than myself that when you have an engine issue where it's running, but likely to stop, do not CHANGE anything unless you are pulling power to land. You change something inside the engine, you induce the potential for earlier failure.

Probably smart...

Now I'm going to go do math for a while and figure this out at a theoretical level.

 

[Huckster79]

I would think that, if you still have *partial* pressure, higher RPM would keep higher pressure, but depending on the reason pressure is dropping, you might go to zero faster.

I think you're right that once there is *no* oil pressure, you might be able to keep the engine running for a minute longer if you reduce power, but I don't think you'll really get it stabilized at best glide - I bet it'll seize in a minute. @Ted DuPuis might know?



It probably depends what the problem is, but I think in general you'd be correct.



Yes! And I'm going to hopefully do some math and prove you right.



Might be % power based to some extent as well. If it's strictly RPM based, I'm gonna shove the throttle all the way in and pull the prop back to something fairly low to get as much power out of those RPMs as I can...



I think it depends on the airplane. Some planes are very sensitive to how the propwash hits the wing and the tail.

It can also be a psychological thing. Pull means up, right? So a pilot losing power shortly after takeoff will tend to pull, so you need to *think* "push" just to cancel out your subconscious desire to pull.



I agree with your thinking, but I'm not sure what your last sentence means? Climb at Vy until you don't have enough power left to continue climbing, then max forward speed (which is still Vy at that point) until you're down to Vg or something? I think @Salty is probably right that Vg regardless is the best way to convert as much chemical energy to kinetic+potential as possible. Probably still aircraft type dependent to some extent.



What if you're over a suitable landing area, but there's an airport nearby and you'll be able to glide to either the suitable landing area or to the airport for the entire time you're flying toward the airport? I'd maintain altitude to the extent possible and head for the airport.



As little drag as possible = slowing to Vg so as not to unnecessarily lose energy to parasitic drag, in my mind. That means at least a momentary climb.



Probably smart...

Now I'm going to go do math for a while and figure this out at a theoretical level.

I'm looking forward to your math project. As I can see both the "Climb argument" and the "Maintain Argument". I'm not sure (honestly-not said in skeptical way) if giving up those knots/mph for a climb would gain you enough altitude to glide more distance than you would have gained by maintaining cruise as long as possible not giving up that speed... Just thinking of my lil bird, I cruise around 110mph Best Glide around 70, climb at 70 is probably around 700fmp, so would giving up 40mph be worth it? Losing 3/4 of a mile of distance every minute to gain 700 feet? I guess the math would be about glide ratio and how much glide that 700 ft gives me???

Im anxious to see your math... Then we obviously have to apply/translate it to our birds and their characteristics...And then the unknown variable in the discussion "How much longer will the engine run"... The "right" thing to do may be different if she has 1 minute left vs 15 minutes left....

If nothing else this is a good discussion to exercise our decision making part of our pilot brains, as there is numerous and varying factors here that could create multiple decisions that will fall on varying parts of the "Right-Wrong" spectrum. I think even if a clear single answer cannot be arrived at the exercise of this discussion is good for us...

 

[Ted]

I would think that, if you still have *partial* pressure, higher RPM would keep higher pressure, but depending on the reason pressure is dropping, you might go to zero faster.

I think you're right that once there is *no* oil pressure, you might be able to keep the engine running for a minute longer if you reduce power, but I don't think you'll really get it stabilized at best glide - I bet it'll seize in a minute. @Ted DuPuis might know?

Without oil pressure you can get an engine to last a remarkably long time, but the catch for that is having it at idle. At any significant kind of power, yeah you'll be producing too much heat and the thing will seize pretty quickly.

I used this trick once in my 1969 Cadillac Fleetwood Series 75 when the dime-sized hole in the piston consumed enough oil that after a 600 mile drive (at 12 MPG) the oil light came on going down the highway at 85. I idled my way probably 25 minutes to the next exit, dumped oil in it. Engine was fine other than the dime-sized hole in the piston.

Don't run your engines without oil, kids.

 

[Checkout_my_Six]

yup....a '69 Caddie is similar to my TSIO-520.

 

[FormerHangie]

In this fellow's case, the engine ran 17 minutes, and he was flogging it:

Engines with splash lubrication and two strokes run without oil pressure for their entire working lives. As long as an oil film remains, the engine should survive, especially our pushrod aero engines. OHC engines that lose oil pressure almost always fail the cam bearings, the bottom end remains intact.

If I were in that situation with oil pressure sinking and oil temperature rising, I'd throttle back to a little over best glide speed, declare an emergency, and head for the nearest airport. I bet the engine would last long enough to make a normal landing. Not too sure it would survive a go around.

 

[KaiGywer]

Curious, not cantankerous; would you pull the handle engine out with hayfield/frozen lake (if we didn’t have tons of snow), nice par 4, etc available?

I certainly get it at night, over inhospitable terrain, etc... but idk if I would if I had a suitable landing spot... just seems like there’s still danger involved, clipping a tall tree, ect- that I could avoid gliding to a suitable landing area. Then again I’m not faced with the conundrum as the ‘47 wasn’t outfitted with that option

It's a worthwhile question. There was a similar thread about this on the Cirrus forum, and the overall opinion was to pull the chute. Most fields and natural frozen lakes aren't going to be that smooth, and you're still going to be landing going at least 60 knots if not greater.. that's a lot of energy to dissipate. you will most likely be damaging the airplane anyway even if it's just the landing gear. And that's assuming you nailed the pattern and approach perfectly the first time you're ever doing a no engine landing in a plane that gets very draggy with full flaps or very fast without.. might as well glad yourself to a good area and then pull the chute


Nope! But you did have four times as many engines!

We had a local Cirrus driver make that call here a couple months ago. Started losing oil pressure at 8000ft and turned back towards the airport. Eventually lost engine power a few miles short of the airport. At one point he told ATC he was pulling the chute, but decided instead to land in a snow covered field. His reasoning was the high winds that day (~35mph with gusts), power lines and unhospitable terrain below and the chute would have taken him that direction. Instead, he pointed it at a field and landed with very little damage to the plane. Pics in this link:

https://www.kfyrtv.com/content/news...lane-landing-south-of-Bismarck-505034032.html