Engine failure SID vs go around pattern

[PatagoniK]

I would like to know what would you do in the case that you are approaching one engine (lets say on a 737) and you have to go around from a runway where you have published engine failure after V1 take off and go around procedure. Would you follow the missed approach procedure or the failure after V1? Where did you get it from?

Best regards.

[judge11]

There will, no doubt, be those who contribute to this thread who will be able to quote cahpter and verse for you. As a lowly line pilot, I have always been instructed (in the UK) that a single engine go-around from at or above DA/MDA follows the MAP; from below DA/MDA the emergency turn procedure. I believe that the logic is tied into the obstacle clearance criteria in that if you are already at DA (say) 200 feet above the runway you already have clearance above any obstacles considered a threat to you losing the engine at V1/Vr.

[PatagoniK]

I agree with you judge11, and your answer is logical, but I would like to know, apart from what we were instructed, if there is something "on the papers" that clearly states what to do on such cases. For example, what I read (not too much by the way) is that the definition of "missed approach" doesn't considers 50% of the available thrust. Finally, everybody applies what they consider to be more "conservative" or logical but nobody can say: -the flight manual recommends this or that-.

Thanks for your time.

[mcdhu]

.........come in JT or Old Smokey - please!!!
cheers,
mcdhu

[Floppy Link]

...plus remember that when you go around on one engine you are a runway length or so short from where the emergency turn procedure starts - thus giving lots more room - I was told to always follow the missed approach procedure (757 / 767).

[PatagoniK]

What you say looks right to me, but I can't say you are wrong if you tell me you follow the after V1 engine failure procedure instead.

[RYR-738-JOCKEY]

For a twin-engine departure (SID) required climb gradient is 3,3. For a contingency procedure (emergency turn, single-engine) req climb gradient is 2,4. Then for a standard missed approach it is 2,5. I have always been taught that if you're single-engine at or below DH/MAP, then you shall follow the contingency procedure. So for instance if you loose an engine below DH/MAP, then following the standard missed approach can get you in trouble.

[PatagoniK]

Up to now, I found very interesting points of view, but most of them are different from the others and that's the reason I posted this question.

I think that we all should agree in one single procedure (of course, I have no idea which one is the correct one). Some people say that is more conservative to take a single engine go around like a single engine take off, adding that you are higher, so you will always be "covered". Others say that a go around is a go around, not taking care of how many engines do you have. As I'am learning for you guys there are some other interesting theories, but at the end I don't really get to understand which one is the right one.

[RYR-738-JOCKEY]

To assume that you will be higher just because of the fact that you are commencing a climb at DH/MAP instead of at rotation on the rwy is like taking a wild guess of how your profile will look a couple of miles ahead and it is very foolish. Keep in mind that for a SID in mountainous terrain you can have an additional required climb gradient, f.e.x 8% till passing a certain point/altitude. You have to be certain that you will be able to achieve obstacle clearance in the missed approach path before making a decision like that. But I know most of you guys live in relatively flat areas and you don't need to take such factors into consideration, however applying such a rule-of-thumb in every situation is not recommendable.

[Capt Pete]

For JAR performance and a two engined aircraft landing from an instrument approach, the aircraft needs to be able to comply with both the following conditions:

1 With both engines running and in the landing configuration, achieve a climb gradient of 3.2% This is essentially a baulked landing and go - around.

2 With the critical engine inoperative and gear up with missed approach flaps, the aircraft needs to achieve a climb gradient of 2.1% from CAT 1 or 2.5% if decision height is below 200 feet.

In the design of instrument approaches PANs ops requires the missed approach phase provides 30m obstacle protection based on a 2.5% gradient.

So worst case and heaviest landing weight, on a cat1 approach with one engine inoperative, at the missed approach point the aeroplane if handled correctly will achieve at least a 2.1% climb gradient. If following the published missed approach you would be converging towards the 2.5% obstacle plane considered in the missed approach design, but the minimum obstacle clearance being provided is 30m on the intermediate part.

This is not to be confused with take of requirements which have a lower obstacle clearance limit, as low as 15 feet when launching from a wet runway and based on a 2.4% gradient.


All very boring I hear you say so whats the answer. Each airfields missed approach climb gradient needs to be considered if contemplating a single engine missed approach at max landing weight from minimums. I would suggest you land !

ref: JAR Ops 1 510 Landing Destination and alternate aerodromes
PANS Ops 1 volume 1 section 3.6, missed approach

[Piltdown Man]

Pat - the bit you forgot was that before you commit yourself to an approach, you should know that you can achieve the required MAP climb gradient, N-1. This should preferably be done in the crewroom before departure. As for what you do when, RYR-738 is in my opinion, spot on.

PM

[RYR-738-JOCKEY]

Another thing...you are uncertain about which theory is the correct one. Well all I can say is that the regulations/limitations/numbers are there..you can choose to go by the book, or you can apply common sense...which might not be the correct thing to do. But when the **** hits the fan, I'm quite sure that many of us won't have time to look up the contingency procedure, but that's another case.

[PatagoniK]

Capt Pete, what I understand is that every CAT 1 missed approach procedure should comply at least with a 2.1% gradient so you can fly it with one or two engines, did I get it right?

Of course this is a theoric discussion and I agree with the last posted by RYR-738-Jockey, but is good to have some fine information for that late night cockpit discussions.

[john_tullamarine]

Not a simple situation.

(a) first off, if the runway has a terrain problem in the overshoot, can you go someplace else .. either another, more benign runway, or a different airport ?

(b) if you propose to adopt the takeoff OEI procedure, how are you going to position yourself appropriately for tracking ? This is probably a lot easier these days with GPS to assist. Maybe you need to increase the minima to account for this so that you aren't trying to miss the rocks when you aren't all that sure just where you are ? Do you have the data and skills to do the sums .. ahead of the operation ?

(c) if you propose to follow the miss, then you had better be sure about the obstacle clearances if there is any terrain of note. Similar comments to (b) apply here as well.

(d) with an ILS, some would adopt the land anyway approach to the problem if there is no better option to commencing the approach.

The better operators will have had their ops engineers address this problem and publish recommended escape procedures where necessary for the particular runway.

The worst strategy is to have none .. and then worry about it just after you have pushed the throttles up for the miss ... but, then again, if you don't have a strategy ahead of time ... you probably wouldn't see any problem worth worrying about during the miss ?

[PatagoniK]

Finally, and thanks to all the people that gently posted their opinions I arrived to the answer to my question: If you are going around one engine, simply follow the go around procedure.

It will be too much to hold the approach chart, the missed approach chart and the engine failure after V1 chart, it's just too unnatural on an approach!!!

Thank you all for your kind help.

[PantLoad]

So, all is well, all engines are purring, DA is reached, can't see to land. "Go-Around, Flaps" (Airbus callout) Then, as the thrust comes up, one coughs and quits.

Uh.....

Gee, the IAP says we need 7% climb gradient to do the published MAP.

Uh...

So, what is our climb gradient OEI with this weight and density altitude?

Uh....

Gee, I wish we had briefed on this before we bagan the approach.

Uh...

Well, where exactly is the terrain?

Uh...

So, do what makes sense: Do a max-effort climb straight down the runway. (As far as I know, they haven't built any mountains on runways.) When you get to the departure end of the runway (It's that long, narrow thing on the ND), fly the "Engine Failure on Takeoff" procedure. Advise ATC.

Will you, at some point, get on the ground safely? (Nobody hurt, no metal bent) Yes.

End of discussion...


At my old airline, the charts are entitled, "Engine Failure on Takeoff or Missed Approach".


Absent clear direction from your brilliant management, do what makes sense.


PantLoad