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Emergency Landing Pattern (ELP) numbers

RV7AJeremy

Well Known Member
Looking for suggested altitudes and airspeeds for flying an ELP in a 7.
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If you would like more info on this you can download the publication here:
http://static.e-publishing.af.mil/production/1/af_a3_5/publication/afman11-248/afman11-248.pdf It's an interesting read.

Thanks in advance
 
I had to look up the meaning of WTD on the first graphic.

So others can save time...:)

WTD = Wing Tip Distance


Brought to you by the DOA - Dept. of Acronyms...
 
I really thought this would generate more discussion. Anyone have any suggestions? How much altitude is lost with an engine out in a 180 degree turn?
 
I really thought this would generate more discussion. Anyone have any suggestions? How much altitude is lost with an engine out in a 180 degree turn?

Hi Jeremy

There has been a few threads on related topics (if you haven't already read them)... do a search for 'impossible turn' that had a lot of discussion on the return to runway on engine failure. Lots of talk about best glide...height lost etc.

Another is 'best glide'...Kevin Horton has done quite a few flight tests...with engine off, and prop stopped or windmilling. Also an interesting read.

I guess the main problem is we all have different configurations, and one persons plane is going to behave differently from another's...

Some report best glide of 80 knots.... some go as high as 95 or so with different sink rates.

I'm sure others will chime in... but it's going to come down to determining your own numbers for your aircraft condition.

Chris
 
very interesting!

Well Major Jeremy, I am happy that people with your qualifications are addressing issues like this!
I can't say I've read the 262 page guide to flying a T-6, but I do love to see them do approaches to our local field....not sure I've ever seen them do this particular practice though?
anyway, I doubt that I'm ever at the high-key #1, more likely 5 miles from the field, at circuit height ( 1000' agl) so my procedure for engine out is more like....
nose down, best glide, point at the numbers.....can't make it?....aim for the golf course! ( there's a golf course on final at pretty much every airport in the world, right? :)
bonus!...usually lots of doctors nearby when you slide to a stop on the 9th green.
-negatives: usually lots of lawyers around as well! :(
 
Thanks for the response guys. My intent was to not start another "turn back" thread that has been discussed at great lengths on this forum but rather a discussion on engine out scenerios while enroute somewhere and planning out descent profiles to arrive at a particular altitude (high key) over a field, and then how much altitude I will loose while enroute to the various "key" positions. I think it is a very valuable maneuver and just wanted to generate a bit of discussion about it as I have not seen a lot of talk about ELP's (not take off emergencies) on this forum.

I was at a forum at oshkosh a few years back and the presenter showed the graphic I introduced earlier and it seemed to generate a lot of interest. I have not seen it on this forum yet so I figured some people might find it interesting.

Fly safe everyone:)
 
Jeremy,

My numbers will be reference only, as my plane is a heavy RV-6 with a big motor and clipped wings…you'll likely be able to beat my numbers in the ELP.

This was in Reno at 5000' MSL, and a DA of about 7000', using a best glide speed of 87 KIAS. I practiced several PELs (us Navy guys always like to rearrange the letters ;)), and found that with the prop and throttle left alone, I needed to hit high key at 1800' AGL and low key at 900' AGL to make consistently safe/stable approaches. With the throttle and prop full forward, I could work it down to 1500'/750'.

Have fun practicing them, and let us know what you come up with as a god target. Its a great maneuver to have in your hip pocket, as you know!

Cheers,
Bob
 
Thanks Bob, that's EXACTLY the info/discussion I was looking for. I am absoutly going to pratice in my aircraft but it's nice to have an ish number to start from. I figured 3k agl (what we used in the t6) might be a bit strong:D
 
Jeremy,

I think 3K would make a good RV "Double High Key". The wing loading is much lower than in your T6, and the sight picture on final won't be nearly as steep?it'll probably seem pretty docile.

I was a little surprised the T6 calls for 3000'/1500'?I just flew an L-39 and we used 3500'/2500' at 140 KIAS in the SFO pattern (for Gil...Simulated Flameout?didn't want to give you another Easter Egg to hunt for! :p). Then again, the -39 is straight-winged and light, and the T-6 is designed to get guys ready to move to jets?so its probably a great ELP trainer. I'll bet its a bag o' fun!

Cheers,
Bob
 
2000-1000

I have done quite a few now, with both my RV's and have found these numbers:

High key 2000 AGL

Low key 1000 AGL

I aim for 1500 AGL midway beetween high and low key, and 500 AGL on base.

These numbers gives me a margin so I can compensate for winds during the ELP.

I initially aim for 1/3 down to RWY and when landing is assured, (usually on base) I move the aimpont to the T/D point by lowering more flaps and sideslip alittle if neccesary.

I let the engine run at idle, and the C/S prop fully fwd.
To compensate for the idling engine, I set t/o flaps when entering hight key. ( I fly the pattern at 75 KIAS)

I've found that the glide-distance increases quite alot with the C/S prop set to coarse. (20-30%)
However, I don't want to do practice ELP's with the prop that way.
Therefore I have the coarse-option as an emergency "strech-the-glide option" schould I need it.

During practice, I train on intercepting the ELP pattern anywhere during the 360 turn, just in case I won't be able to start at 2000' AGL directly overhead a planned landing site in an actual engine failure.

BTW: I always plan to do the ELP as a full stop landing. This is because the engine is cooled rather much during the ELP and I don't want to add full power on a cold engine to do a t & go afterwards.
This is specially true during winter time ofcourse.

(yes, I know I baby the engine, but it's MY engine... :D )


You dind't mention if you have a FP or CS prop? Since the glidedistance is pretty different on those two, the corresponding numbers will probably vary quite alot... you schould find the numbers for your aircraft. It's pretty easy and fun too! :)
 
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Bob, the T6 is a blast to fly; I love that plane!

AO.Frog, thanks for the numbers. I have a C/S prop so they should be close. Can't wait to fly this thing!
 
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