Best bank angle for a engine failure turnback

[pelmet]

In a single of course.......

"A longstanding question is what bank angle would result in the least loss of altitude during such a maneuver. The answers produced by the Pilatus tests were, respectively, a 2,350-ft. loss at 15 deg., 1,320 ft. at 30 deg., and just 1,005 ft. with a 45-deg. bank. Another discovery to consider: It took 46 sec. to complete the turn back to the runway at 45 deg. of bank, whereas the 15-deg. banked turn required 161 sec., or four times as long. Furthermore, the 45-deg. banked turn had a turn radius of 1,450 ft., versus the 5,050 ft. required for a 15-deg. bank."

And don't forget to turn into wind for the turnback.

By the way, I don't believe their minimum altitudes. I think it is skewed as they wanted full flap and landing gear extension times not only considered but considered separately.

http://aviationweek.com/business-aviati ... gine-fails

[digits_]

Intuitively I'd say whatever angle of bank just doesn't make you stall at your best glide speed. It minimizes the turn radius yet maximizes the glide distance.

[ahramin]

Uh digits, your best glide speed changes with bank angle.

[digits_]

Uh digits, your best glide speed changes with bank angle.

You're probably right, a higher best glide speed in a turn would be expected, however accelerating towards that speed will cost you gliding distance (while going the wrong way), and when you are out of the turn you are at a speed higher than your best glide, which will again cost you a bit of gliding distance.

So if you fly the best glide speed throughout the manouevre and use as much bank angle as possible without stalling, that should give you a fairly close to optimal solution.

If someone can calculate it exactly and/or explain where I might be wrong, I'd definitely be open to a more well founded explanation.

[ahramin]

I think I'll just stick with at least 45°.

[Jean-Pierre]

Did they try up to 90? It got better and better and then they just stop?

[CL-Skadoo!]

Need some Colonel Sanders insight on this one. Where be he?

[photofly]

There's a PDF by David Rogers on the subject. Can't find that, but here's a precis:
http://www.nar-associates.com/technical ... sible.html

There's also this update:
http://www.nar-associates.com/technical ... screen.pdf

[Big Pistons Forever]

AOPA did a study of the accident record for engine failure after takeoff. The conclusion as I recall was that a turn back was 8 times more likely to result in a fatality then gliding straight ahead and taking your lumps with whatever you wind up hitting.......

[photofly]

Of course if the only thing you'll hit straight ahead is the water in the middle of the Humber Bay, it's the middle of December, and nobody thought to bring life jackets, then turning to one side or the other starts to look extremely attractive.

[Big Pistons Forever]

Photo

In your example the statistics indicate that you are more likely to die from the stall spin resulting from the botched turn back then succumbing to hypothermia.

The sad fact is that in the real world pilots, even quite experienced pilots, don’t execute the turn back maneuver very well, and botching the maneuver often results in hitting the ground in a steep nose down, banked attitude. NASA crash tests clearly show this kind of impact has the highest potential for fatalities

[photofly]

I don't think there are any reliable statistics on the subject. How would you know how many pilots make successful landings after turning back? There's no requirement to report.
Either way, I practice the turnback from 500 agl, often. I'm a believer that training a manoeuvre improves ones chances.

When it comes to ditching, I'm not worried about hypothermia, I'm actually worried about drowning in the first five minutes. However terrible a pilot I am, I know I fly much better than I swim.

[anofly]

some of the ferry fellas wear the survival suits, but mid atlantic swear they will take them off, they are not going to bob around for 10 hours waiting......

[photofly]

I have a comfortable survival suit, and have been very happy to wear it. But not on every flight.

More generally, I'm innately suspicious of one-size-fits-all solutions to difficult situations. The "never turn back below 1000agl" rule seems to me to be just such a one-size-fits-all rule. There are lots of places where the field ahead is longer and even smoother than the runway you just took off from. But there are lots of places where very much the opposite is true. Accepting that turning back is a risky manoeuvre for most, the way to put oneself at the top of the pile in terms of achieving success is to practice it, then brief it.

[pelmet]

AOPA did a study of the accident record for engine failure after takeoff. The conclusion as I recall was that a turn back was 8 times more likely to result in a fatality then gliding straight ahead and taking your lumps with whatever you wind up hitting.......

There is probably some validity to the study but I emphasize "some". Likely, most of the people who turned back had never practiced doing so and were not prepared to do so either.

I fly quite a few different aircraft now at different locations and to be honest, it surprises me how often I finish a flight and when mentally reviewing it, realize that I did not even review such a procedure prior to takeoff. But when you are in a location like LA where there is literally nothing reasonable to land on straight ahead at many airports, you seriously want to consider a turnaround and it is frequently possible. Long Beach has parallel runways and if you do a 180, you can be set up at least for a grass landing if not onto the parallel. Flying an LSA out of other single runway airports has you at well above 500 feet by the end of the runway with plenty of room to maneuver.

The idea of having a general policy of mindlessly proceeding straight ahead or nearly so that includes airports and situations such as this(and there are many similar ones all over) just because it is statistically safer can at times be near suicidal in my opinion. You can "take your lumps" by always planning on landing straight ahead if you want, but I prefer to consider some of the other options that may be available at a particular time.

Remember...a turnaround back toward the runway doesn't mean that you should only be willing to land on the runway. There may be good clear areas part or most of the way through the turn that can be safely reached. The goal isn't necessarily the runway. Just the clear area.

[C.W.E.]

In your example the statistics indicate that you are more likely to die from the stall spin resulting from the botched turn back then succumbing to hypothermia.

Does anyone in the flight training business train pilots to do the turn back manoeuvre at a safe altitude anymore?

The stall spin problem is a result of improper handling of the airplane.

[Big Pistons Forever]

Sorry for the thread creep but I find this whole straight ahead vs turn back sad because it shows how poorly we pilots in general evaluate risk.

The actual time where there is dispute seems to be from about 400 feet AGL to 1000 ft. I would suggest a turn back below 400 ft is not viable for most light aircraft and at a 1000 ft you have real choices. So we are talking about 60 seconds or less where there is debate.

I know the successful turn back feeds the secret “hero pilot” fantasy we like to think we epitomize, but again statistically there are many more likely scenarios where we are more likely to come to grief. If you are the average PPL and are looking for something to practice start with landings, crosswind, short field and normal. If you are going to bend an airplane
, a landing gone bad due to a pilot skill deficit is most likely. If can’t touch down in the correct landing attitude near the pre selected touchdown point, everytime, practice more.

My other pet peeve is the shockingly high number of engine failures caused by the pilot. Learning your airplane systems, doing good walk arounds and having good check list discipline will significantly reduce your chances of having the engine fail. The best way to deal with an engine failure is to not have the engine fail in the first place.

The bottom line. Your proficiency as a pilot should not be measured by your perceived ability to execute a low altitude turn back or not, it should be IMHO be how accurately you can execute all of the maneuvers required for a normal flight and how well you plan your flight to mitigate foreseeable risks.

[Big Pistons Forever]

CWE

Practicing turn backs “ at a safe altitude” is IMO, negative training because the big issue with low altitude turn back is ground rush which results in the unconscious desire to pull on the control wheel. As someone with a lot of low altitude flying experience I can state that significant training is required to be competent in that environment particularly when aggressively maneuvering.

The other issue is there is a big difference when you are at 3000 ft and you know the engine is going to fail, over when it happens with no warning at 500 feet...

Like I said in my previous thread, you can train for the event that is not very likely and where the danger zone exists for only 60 seconds, or you can train for all the other much more likely scenarios and expect that if the engine fails below 1000 ft you will work at establishing the correct attitude for best glide and concentrate on keeping the aircraft under positive control as you glide straight ahead or make only moderate turns so that when you hit it will be wings level with a slight nose up attitude, the statistically most survivable crash attitude.

[photofly]

If you are the average PPL .... If [you] can’t touch down in the correct landing attitude near the pre selected touchdown point, everytime,...

For those of us that can, do we have your permission to practice other stuff? Not everyone in this thread is the "average PPL".

[pelmet]

To be honest, I consider the idea of "gliding straight ahead and taking your lumps" to be very dangerous. We should all be prepared to turn. This does not mean that an attempt should be made to turn through the more than 180 degrees required to land on the reciprocal runway. It may be as small as a ten degree turn that is required or perhaps an easy 60 degree turn toward a clear area instead of plowing on ahead regardless of the obstacles.