Losing Engine On Takeoff

JustinPinnix

Pre-Flight
Joined
Oct 28, 2006
Messages
85
Location
Raleigh, NC
Display Name

Display name:
Justin
Last night, I read Julie Boatman's article in this month's AOPA pilot about engine failures on takeoff. She claims that a plane in a high-angle climb will stall when power is removed. The removal of power causes the airplane to descend rather than climb. This changes the angle of the relative wind. This, in turn increases the AoA leading to a stall.

So, I tried it in my Cherokee (at 3000 AGL of course). I couldn't make it happen. As soon as I pull power, the nose drops. The airspeed remained at about where it was (the article warns this will be slow to respond). The stall light never came on, nor did the controls get mushy.

Am I doing this wrong, or does it only affect certain types? I'm surprised that in 5+ years of flying I haven't heard more about this danger.
 
An airplane will not stall in that situation if the nose is lowered to a proper glide angle soon enough.

A common error when underpowered, or without any power when at low altitude, is for pilots to keep pulling the yoke back in a primitive but uncontrolled reflex to climb the aircraft. I think it may be because of a subconcious disbelief of yeah, we're going down this time! I see pilots do it during flight training in all sorts of really low level flying, regardless of available power and especially at night.

JustinPinnix said:
Last night, I read Julie Boatman's article in this month's AOPA pilot about engine failures on takeoff. She claims that a plane in a high-angle climb will stall when power is removed. The removal of power causes the airplane to descend rather than climb. This changes the angle of the relative wind. This, in turn increases the AoA leading to a stall.

So, I tried it in my Cherokee (at 3000 AGL of course). I couldn't make it happen. As soon as I pull power, the nose drops. The airspeed remained at about where it was (the article warns this will be slow to respond). The stall light never came on, nor did the controls get mushy.

Am I doing this wrong, or does it only affect certain types? I'm surprised that in 5+ years of flying I haven't heard more about this danger.
 
Last edited:
I pretty much agree with Julies article, she basically says the same thing that I and a few others such as Barry Schiff have been saying for years. Pilots of both single and multiengine airplanes are being mistrained and in some cases killed, because of a serious flaw in the way that they are taught to fly takeoffs.

David hits the nail squarely on the head, where Julie missed it a little, it is not the failure itself, it is the immediate reaction to the problem that sets the stage for a bad outcome, if you are flying at a speed well above vyse, you can actually convert that speed into altitude and in most cases your immediate reaction to the failure does exactly that.

In a twin it is even more critical, if you are holding blue line and lose one you have to immediatley push the nose down to regain single engine climb speed, only one light twin made today will do that, if you are above blue line, not only do you have a little cushion, but in a 310 or a baron you can gain some altitude while identifying and dealing with the dead engine.

But the FAA continues to insist on cllimbs that I personally feel are executed at a speed well below that speed that is really safe and efficeint in case of an engine failure.
 
Ok, so for single engine planes, what departure climb speed DO you recommend, and why? (I know you said the above, but can you add any particulars?)

Thanks -
 
I teach my students to accelerate to a cruise climb speed and maintain that, usually works out to vyse plus 15, but check you POH. Of course there are times when best rate or best angle of climb need to be used for obstacle clearance,
 
Last edited:
wesleyj said:
I teach my students to accelerate to a cruise climb speed and maintain that, usually works out to vyse plus 15, but check you POH. Of course there are times when best rate or best angle of climb need to be used for obstacle clearance,

You are joined in this by such luminaries as John Deakin, who talked about this in his AvWeb series on turbocharged engine management, pointing out that it also keeps the turbocharger cool, avoiding the high temperatures which tend to be associated with climb.

Dr. Bruce can speak better than I to the pilots of twins who ignore the guidelines for takeoff/climb speed when confronted with heavy loads/short runways/high density altitudes. Your practice encourages more thought being given to this area.
 
I always climb in a single at Vy or Vx until I'm clear of any obstacles or at or above the minimum climb profile for the instrument departure, then I transition into a cruise climb. In nearly all the airplanes I fly 8 degrees nose up works out to a comfortable climb well above stall speeds with good forward visibility and at least 500 FPM climb rate.

In a twin, it's VYse until pattern atltitude, and then the same profile. I really am not worried about an efficient climb in a light airplane, the way I might worry in a jet.
 
I've always been a cruise climb guy. John Deakin wrote it out in a manner that helped me understand and analyse it better.

One has two types of energy: potential and kinetic. A steeper climb produces more potential at higher altitude; a shallower climb produces more kinetic at less altitude. There are some aeronautical engineers on the Beechlist that did prove there is more total energy at Vx if there is a failure, but they fail to consider pilot reaction (and with the experience they have, reaction may not be an issue).

My second tour overseas, we flew at tree top level at about 140 knots because the enemy began using shoulder fired missiles. Our reaction if we took a hit and lost an engine was slightly back on the cyclic; quickly look left and right 20 to 30 degrees, pick your spot and autorotate in. Maybe that's a help in my reactions.

I'm not a Vx or Vy guy unless you just have to be there. From longer runways, I see training flights all day teaching Vx Vy departures. I see folks routinely use Vx and Vy from a 7,400 foot runway. I just shake my head. With that much runway, I'd much rather be lower; faster if something went wrong; excellent chance I can put it back on the runway.



You actually can clear an obstacle better wheels on the ground longer or accelerating in ground effect and pulling up over the obstacle; then, nosing over. Deakin also demonstrated this. But, it's probably not best to teach that to new pilots.

Always something to learn and improve upon.

Best,

Dave
 
Dave Siciliano said:
You actually can clear an obstacle better wheels on the ground longer or accelerating in ground effect and pulling up over the obstacle; then, nosing over. Deakin also demonstrated this. But, it's probably not best to teach that to new pilots.

Could you point me to to which Deakin article or did you get to go to an APS (Advance Pilot Seminar) ?
 
Jeff, I'm not sure. I thought is was one of his Pelican's Purch articles--on AvWeb. He may have also posted that on the Beechlist.

He showed how POH numbers could be beaten by accelerating to a faster speed on the ground or while staying in ground effect (the plane does accelerate faster there than by pulling it off the gound at POH recommended speeds to up to over 100 knots--of course, depending on the plane--his was a V-tail Bo).


By letting it accelerate faster, pulling up over the obstacle, then putting the nose down again, one could beat POH numbers over a 50 foot obstacle by a meaningful amount. It takes more pilotage and could get someone in trouble fast if they didn't know what they were doing or if the execution wasn't proper.


Best,

Dave
 
wesleyj said:
But the FAA continues to insist on cllimbs that I personally feel are executed at a speed well below that speed that is really safe and efficeint in case of an engine failure.
Can you provide some reference to this FAA "insistence"? I don't think I've ever seen such.
 
Dave Siciliano said:
Jeff, I'm not sure. I thought is was one of his Pelican's Purch articles--on AvWeb. He may have also posted that on the Beechlist.

I found the archives... I'll search it when I get home.
 
I don't know if you are talking singles here. But I'd *much* rather climb at Vy and be higher when the engine quits. If one isn't capable of understanding that you must PUSH when it quits .. Well. You shouldn't be flying.

It seems to me that it's foolish to take the *easier* for people that just don't understand a simple concept. Instead of training the proper reaction to ensure that you have an improved chance of a successful engine failure landing.

Now I'm not talking about twins. I don't know hardly anything about them and can barely fly them.
 
Ron Levy said:
Can you provide some reference to this FAA "insistence"? I don't think I've ever seen such.

Go Take a checkride and see what happens if you fail to maintain Vyse or Blue line to 400 feet, take a 135 ride in any twin and go over blue line before 400 feet.
 
jangell said:
I don't know if you are talking singles here. But I'd *much* rather climb at Vy and be higher when the engine quits. If one isn't capable of understanding that you must PUSH when it quits .. Well. You shouldn't be flying.

It seems to me that it's foolish to take the *easier* for people that just don't understand a simple concept. Instead of training the proper reaction to ensure that you have an improved chance of a successful engine failure landing.

Now I'm not talking about twins. I don't know hardly anything about them and can barely fly them.

problem is, by the time you react and stop the normal pulling back, you have already lost so much that in both altitude and airspeed that you are in trouble
 
wesleyj said:
Go Take a checkride and see what happens if you fail to maintain Vyse or Blue line to 400 feet, take a 135 ride in any twin and go over blue line before 400 feet.
I've done that, and never had a problem between my 135 days in Aztecs in the late 70's or taking a 141 instructor check in a Cougar in the late 90's. I haven't taken a multi check with the Feds since then, but my students have, and not been dinged for going for Vy ASAP, and even cruise climb if obstacles are not a factor. Perhaps your FSDO is playing by a different set of rules. In any event, I do not think you can find an FAA document which requires, no less merely suggests, staying at Vyse/blue line until 400 AGL in a light twin.
 
Vysse every time for me, except for summertime at Pickett Grooms, where it was marginal even 1000 under gross. I went to Vysse at Gastons, too.
 
Sorry, Bruce -- I disagree. In a single, altitude is life, but in a twin, speed is life, so in a twin, I want all the speed I can get as fast as I can get it. Once airborne, I put my flight vector just over whatever obstruction is out there, and take however much speed I get up to Vy, and then hold Vy to 500 feet or so, and then set a cruise climb. It's a whole lot easier decelerating from Vy to Vyse after one fails than it is to regain Vyse if one fails at that speed.
 
Sunday I did an hour for the Wings program with my CFI, and this is one of the things I wanted to do. Of course the reaction time was a lot quicker, knowing what was happening, but I lost a hundred feet in altitude just establishing glide speed. That is definitely not much time if the engine
quits a two hundred feet. :hairraise:
 
Ron, ron....

In the Seneca, Vysse is Vy. Blueline and Vy are coincident. :) :) :)
VERY easy aircraft to memorize the numbers....

And if I can't get Vysse before committing to leave the land straight ahead enviromnent, I need less load or a bigger runway.....short grass strips being the only exception.

It's quite a departure briefing: "if an engine fails, we're in the trees". My wife doesn't like that one. I need 4000 feet to not have to give that briefing. Sigh.
 
Last edited:
ladyaviator said:
Sunday I did an hour for the Wings program with my CFI, and this is one of the things I wanted to do. Of course the reaction time was a lot quicker, knowing what was happening, but I lost a hundred feet in altitude just establishing glide speed. That is definitely not much time if the engine
quits a two hundred feet. :hairraise:
Generally, best glide speed isn't a valid target in this scenario...you're not going anywhere except down. You just need to get the nose down far enough to have enough energy for the flare.

Fly safe!

David
 
I can't speak to twin engine stuff, but in a single engine I believe that Vy is the number to use once any obstacles have been cleared at Vx. I fly Vy to about 500' - 1000' AGL, the lower the nose a bit for better visibility, cooling, and groundspeed. I don't go to a true cruise climb until I have about 1000' to 1500'.

As was said above, in a single, altitude is life if the engine fails. Consider that if you double your altitude, you get four times the landing options since the area you can reach goes up with the square of your gliding distance. You also increase your time to get a mayday out, secure the engine, and generally breath and think a bit.

It has been pointed out that it's all about energy. If you're flying low and fast you can pull up and convert some of that speed into height. That works a lot better in a modern high performance glider than it does in a typical light single.

Consider that every second that you're flying you're also losing energy. The faster you fly, the faster you lose it. In fact, the rate you lose it goes up with the cube of your airspeed (drag goes up with the square, power is drag times velocity, so the energy lost per second is proportional to the cube of velocity. That assumes I'm flying a bit faster than my best glide speed so that parasite drag dominates). That means that you're much more efficient at lower speeds.

When I start a take-off run, I put in full throttle and basically leave it there. Ignoring the change in power output of a fixed pitch prop as I accelerate, the engine's basically putting energy into the airplane at a constant rate, regardless of my speed. At the same time, drag is taking it out at a rate dependent on my airspeed. If the two rates are matched, I can't accelerate or climb. If I have an excess of power, I can choose to put it into kinetic energy or into altitude. If I choose to put it into more speed, then the rate at which energy is taken out by drag goes up, so that after 2 minutes, for example, I'll have less total energy than if I had climbed at a lower speed for 2 minutes.

Now lets say that after 2 minutes, my engine fails. If I've used a cruise climb, I have less energy overall and I'm lower. So the first thing I want to do is trade some speed for altitude. However, I'm going pretty fast, so as I pull back and start to slow down (trading potential energy for kinetic energy), I'll still be losing energy at a good rate. As a result, I started with less total energy (due to the increased drag during the two minutes my engine was working), and I lose even more as I trade speed for altitude. I'll end up at a lower altitude than if I'd stayed at Vy for that 2 minutes.

As far as the question of how this would be modified with a very long runway, I'm not sure it changes much. Let's say your engine quits 15 seconds after liftoff. If you stayed very low (in ground effect where drag is very low), your total energy will be higher than if you climbed at Vy, and you'll have used up more runway in front of you, so it may actually be harder to land back on the runway before you run out. If you use a cruise climb, you'll have less total energy at that point (which is good in this case), but you'll have used up more runway. Not sure if you come out ahead or behind.

The problem is when your engine fails just as you leave the very long runway behind. Then it doesn't matter if it was a short or long runway, if you were climbing at Vy you'll be higher and have more options and more time. Both will increase your chances of survival.

Chris
 
bbchien said:
It's quite a departure briefing: "if an engine fails, we're in the trees". My wife doesn't like that one. I need 4000 feet to not have to give that briefing. Sigh.

We're trying Bruce, we're trying! Should be 2600' for 2007 and hopefully 2900' for 2008. Another 3000' or so and Ron and Anthony could even land there.
:hairraise: :rofl:
 
bbchien said:
In the Seneca, Vysse is Vy. Blueline and Vy are coincident. :) :) :)
VERY easy aircraft to memorize the numbers....
Only twin I've ever known where that's true. The ones I know cold (Aztec and Cougar) are 18 mph and 14 knots apart, respectively. Obviously, in those planes, climbing at Vyse with both engines running would be a poor choice, as you don't get valuable altitude as fast, and if an engine quits, you're almost certainly going to end up below Vyse before you can sort things out, and then you have to trade some of that lesser altitude for speed, which just makes things worse.

BTW, I've heard of Vsse (minimum safe single engine speed) in newer Piper twins like the Seminole as the target speed for when you lose one and have to climb, and Vyse (single engine best rate of climb speed) in most other twins, but I've never heard of Vysse (meaning?).
 
Ron Levy said:
Only twin I've ever known where that's true. The ones I know cold (Aztec and Cougar) are 18 mph and 14 knots apart, respectively. Obviously, in those planes, climbing at Vyse with both engines running would be a poor choice, as you don't get valuable altitude as fast, and if an engine quits, you're almost certainly going to end up below Vyse before you can sort things out, and then you have to trade some of that lesser altitude for speed, which just makes things worse.

BTW, I've heard of Vsse (minimum safe single engine speed) in newer Piper twins like the Seminole as the target speed for when you lose one and have to climb, and Vyse (single engine best rate of climb speed) in most other twins, but I've never heard of Vysse (meaning?).
Ugh. Vyse. Vy for single engine ops.

This is one of the reasons Senecas are benign (er....generally).

And yes, I have some GA7 time, and in that bird I would vote for speed. It's forgiving even below Vyse and almost to a fault, but it sure won't climb below blueline.
 
I'm lookin at the P-Baron POH and it shows the following:
Two engine best rate of climb: 115 knots
Best rate of climb speed One engine inoperative: 115 knots.

Isn't that the same as Bruce is saying the Seneca is? Or have I missed something?

VYsse is 87 knots.

Best,

Dave
 
Dave Siciliano said:
VYsse is 87 knots.

Not you too Dave! There's no 'Y' in Vsse (safe single engine speed) and there's only one 's' in Vyse. Bruce has been mistyping Vyse as Vysse for years. I called him on it once or twice and then gave it up as one of those cute little marginally annoying mannerisms that make all of us unique beings.

In my plane Vyse (the blue line on the ASI) is 100 KCAS and Vy (both engines running) is 107 KCAS IIRC. I would have thought that there would be a similar difference between those two speeds in your plane, but since each is dependent on different variables, it's certainly possible for them to be the same in some airplanes.
 
Thanks to Ron for pointing it out. And to Lance for putting up with it. Sigh.
 
Back
Top