Hello,

I was just wondering what everyone thought on an engine out situation.

If you have an engine out and have plenty of altitude, say 6000' AGL, and you wanted to turn 180 degrees after calculating that you can make a field behind you, would you bank sharply (knowing you will lose altitude, but gain airspeed that you can then use to gain altitude again up until hitting best glide speed), or would you bank shallow and make a slow turn at glide speed?

I ask this because the more people I fly with, I find they have a harder time staying coordinated while trying to perform a shallow bank than they do if they roll the plane over to a steeper bank. Simply put, is it better to get the aircraft turned so you can set up for the decent and approach, or rather take things slow?

Thanks for the input...just something I've never heard in training pilots for emergency procedures.

 

I would teach the student to maintain best glide regardless of bank angle. At the same time, I would stay as close to the intended landing point as I could at all times. If you're at 6,000 feet, I really wouldn't care what happened as long as the student kept good SA and had a plan.

There are procedures and techniques. In this case, the bank angle would be a technique. The procedure would be to maintain aircraft control, follow a checklist of emergency procedures, and land at the most suitable location.

 

For some unknown reason, best glide with a 45' bank came to mind. Don't know if that came from a CFI or an article on the dreaded "turn back" conundrum. 6K and how far away?

 

I would perform a slow, on glide speed, and coordinated type turn. 6k is sufficient alt for a 180 but I have no idea in your situation where the airport is(ie how far away). I took a student(mature, really smart, and good stick/rudder guy) up on a flight to test just this question. Got permission from tower and took off from a parallel runway. At 600'(btw I had another area to land just in case something did go wrong) I idled the engine and made it back to the other parallel. We actually had to use flaps to lose altitude and thought about the possibility of making it back to the original runway.


Results may vary.

 

Of course it depends on what aircraft you're doing it in - but for the sake of training say a 172.... Say departure end of the runway and 6000' AGL is more than enough for a 360 degree turn to land into the wind (if that's what you wanted) on the same runway. As a matter of fact you'd probably have to loose altitude depending on position, winds, etc. There's enough time to quickly run through some trouble shooting - and get a back-up landing area in mind should you have miscalculated.

IHMO bank doesn't really matter too much until you're critical on your airspeed/altitude... which may be below 1000' AGL or something.

It may be a good idea for CFIs to teach really tight patterns so students get an idea of how a ~50-60 degree bank base to final feels like with speed/sink rate, etc.... getting a feel of energy lost, etc...

 

Schiff did some tests a few years back, steeper is better. Problem becomes the stall speed goes up so you have to unload in the turn. Your stall speed may be above best glide in a 70 degree bank. They were only lossing 210 feet in a 70 degree banked turn. But he admits that's a bit too radical close to the ground and so came up with the 45 degree bank as a compromise.

Also you have less offset with a steeper bank so less altitude lost wiggling to to line up with the runway.

It's normal on a glider checkride to have a rope break at 200 feet and return to the runway.

 

One thing tought to glider pilots when the rope breaks close to the ground is to do a 45deg banked turn. Next time you get a chance, bring the engine back to idle, trim for best glide and call out an altitude to start a turn at. Use your slow coridinated turn and see how much altitude you loose in a 180deg turn. Then try it again, but this time use a 45deg turn and maintain best glide. You will loose half the altitude in the 45deg bank turn.

 

Thanks everyone for your input. I have also heard of the 45 degree bank aspect of a power off turn with minimal loss of altitude. I was just curious what everyone else has either gone through or tested. As for the given alt. of 6000', I only used that so that I wouldn't get a lot of responses that stated stay straight ahead otherwise you'll cartwheel into the ground trying to turn around. I understand the risks at low agl's, just wanted to find out what the thoughts were on having enough altitude.

I know Martha King teaches steep turns when in the pattern on a power off landing simply because it gives more time to assess the situation when you can level your wings after a 90 degree turn and the steeper turn gets you around to that 90 degrees faster and gives you better fov after leveling.

I am going to try my own tests in both a 172 and Archer. After multiple times, I will get back to you all with the figures of what I found along with what types of days they were done on. Obviously it won't be a science due to winds/temp and density alt. but it may give a little insight into a typical training aircraft's ability to do a 180 in that situation.

Thanks again.

 

You should be able to pull up Barry Schiff's article from the AOPA website. Something like "Engine Failure." He ran through a bunch of different bank angles. Do try it yourself (with a good altitude pad) and see if you get the same results.

 

_The Possible ‘Impossible’ Turn_ is available as a .pdf file here: http://bit.ly/aQq09a

Author - David F. Rogers
United States Naval Academy Annapolis, Maryland 21402
[email protected]
c 1994
Originally published in the AIAA Journal of Aircraft, Vol. 32, pp. 392-397, 1995 with permission.

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Jack