Go Around procedure for One Engine Out

[Ondraayyy]

I understand that some airport under special conditions such as high terrain within the vicinity of it, has their own special engine failure procedure, so as to keep the aircraft within a safe margin from the obstacles around it even with the aircraft reduced performance.

Now the question is, when we execute a go around, do we follow the original missed approach procedure or are we supposed to follow the special engine failure procedure?

Some of my colleague says to follow the missed approach procedure while others to follow the special engine failure procedure...

Can anyone enlighten me on this?

[763 jock]

How many engines are operating? That should give you the answer you are looking for. The engine out go around procedure is often company specific provided by your own performance engineers.

[john_tullamarine]

Not really as simple as that, I'm afraid.

(a) the usual takeoff should only be used for takeoff OEI if your performance folk have done the sums for OEI, as they should have, determined and published words to the effect that the departure is acceptable for OEI.

(b) if the normal takeoff doesn't work for OEI, then there should be published an acceptable escape procedure for takeoff.

(c) when it comes to the miss, neither of the above necessarily fit the profile for the miss (or vice versa, if you prefer). Reasons will relate to speeds, turns in relation to specific terrain (speed/radius of turn) configuration and changes, and position in respect of the runway at the commencement of the miss, tracking and tracking accuracy and so on. That is to say, unless the performance folks have done some sensible sums, and published a way out, you can't necessarily presume that this or that will be acceptable and work.

(d) do all operators look after this stuff ? Not for me to opine - however, for my customers the answer is yes. Same for Old Smokey, Mutt and other ops engineers who have an understanding of frights from the cockpit ....

[Check Airman]

My company publishes separate engine failure procedures for takeoff and go around. A320

[APU_inop]

Depends on type of aircraft, operation and company. Most if not all companies have an EOSID/EOMA procedure for each runway if the published SID/M-APP procedure doesn't provide enough terrain clearance

[neilki]

I understand that some airport under special conditions such as high terrain within the vicinity of it, has their own special engine failure procedure, so as to keep the aircraft within a safe margin from the obstacles around it even with the aircraft reduced performance.

Now the question is, when we execute a go around, do we follow the original missed approach procedure or are we supposed to follow the special engine failure procedure?

Some of my instructors says to follow the missed approach procedure while others to follow the special engine failure procedure...

Can anyone enlighten me on this?
There is debate amongst your instructors about wether to apply Special Engine Failure Proceedure OEI??
I've seen this written on PPRune a handful of times before, but never thought I'd have to say it...
-Please tell me the name of your Airline so everyone can avoid flying it.

[FlightDetent]

Standard Missed Approach procedure designed i.a.w ICAO Doc 8168 requires you to make 2,5% gradient. Warning: there is no allowance for a level acceleration segment, just 2,5% all the way until the MisApch altitude.

For OEI, it is the operators' responsibility to do the math (tkof, enrt and ldg) - at all times. The performance for MisApch from the airworthiness requirements requires is 2,4% for modern twins (Perf class A), and so 2,5 is doable or you must restrict the LW accordingly anyway. So the AOC holder should run the figures for 2,5 (or as charted) before dispatch and later following the prescribed MisApch is enough. Well, until you run out of MAX TOGA time on the remaining engine (maybe keep this element for a later debate).

Cannot speak for quads, trimotors or other performance classes.

A pretty decent layout is (in general)
- AEO at minima or above -> follow the MAPr
- AEO below minima -> avoid close-in obstacles visually and rejoin the MAPr
- OEI at minima or above AND the charted gradient (2,5% unless stated higher) is checked OK -> follow the MAPr
- OEI below minima OR unable to make the published gradient -> follow a specific procedure (most likely the OEI instrument tkof procedure for that runway)

If the above is not sufficient, then by definition we are talking about an airport requiring special performance considerations. The assessment of which is a legal responsibility of the AOC holder, who must then provide the necessary procedure / calculated solution AND training how to apply it to the crews.

That's how I heard it.

[vilas]

Simply stating special engine out procedure is vague. Is it for takeoff or missed approach or both? The takeoff procedure or SID maybe turning you to the right the MA may be turning to the left. Assuming both are in the same direction the vertical profile starts at different points. MA may may make it takeoff may not meet it.

[Ondraayyy]

There is debate amongst your instructors about wether to apply Special Engine Failure Proceedure OEI??
I've seen this written on PPRune a handful of times before, but never thought I'd have to say it...
-Please tell me the name of your Airline so everyone can avoid flying it.
I asked for an answer, not an opinion. Thanks

[Ondraayyy]

Standard Missed Approach procedure per ICAO Doc 8168 needs you to make 2,5% gradient. Warning: level acceleration segment is no longer a design requirement for those, thus 2,5 all the way up to Missed Approach final altitude may be needed.

pretty decent layout is (in general)
- AEO at minima or above -> follow the MAPr
- AEO below minima -> avoid the imminent close-in obstacles visually and rejoin the the MAPr and
- OEI at minima or above AND the charted gradient (2,5% unless stated higher) checked OK -> follow the MAPr
- OEI below minima OR unable to make the published gradient -> follow a specific procedure (most likely the OEI instrument tkof procedure for that runway)




Thank you for the enlightenment :) ;) This answer my question...

[neilki]

A) its not an opinion. It's reflective of the likelihood of CFIT.
B) The answer is -you fly the procedure for each scenario as defined by your Aircraft specific Company provided performance solution..

[pineteam]

On A320 and I believe on any modern airliners you are never limited in climb gradient with all engines operating.
We do our performance calculation using Flysmart on Ipad and we have the engine out go around gradient displayed for awareness so we know if we can comply with the required climb gradient or if we must follow the EOSID.

[neilki]

On A320 and I believe on any modern airliners you are never limited in climb gradient with all engines operating.
We do our performance calculation using Flysmart on Ipad and we have the engine out go around gradient displayed for awareness so we know if we can comply with the required climb gradient or if we must follow the EOSID.

Terrain Performance or Departure Performance?
In the US, the A320 is certainly limited in some Altitude Constraints on SIDs. In fact, ORD just added a lateral half mile to its' DME/Alt requirements, and a heavy 321 on a hot day out of LAS will struggle above Green Dot....

[sonicbum]

I understand that some airport under special conditions such as high terrain within the vicinity of it, has their own special engine failure procedure, so as to keep the aircraft within a safe margin from the obstacles around it even with the aircraft reduced performance.

Now the question is, when we execute a go around, do we follow the original missed approach procedure or are we supposed to follow the special engine failure procedure?

Some of my colleague says to follow the missed approach procedure while others to follow the special engine failure procedure...

Can anyone enlighten me on this?

Hi,

when You do your calculations for dispatch landing performance You will realize that in those kind of scenarios the approach climb gradient will limit your MLW, therefore 2 options : 1) Your ops establish an alternative missed approach if feasible performance wise or 2) you decrease your LW to comply with the missed approach gradient.

[sonicbum]

On A320 and I believe on any modern airliners you are never limited in climb gradient with all engines operating.
We do our performance calculation using Flysmart on Ipad and we have the engine out go around gradient displayed for awareness so we know if we can comply with the required climb gradient or if we must follow the EOSID.


Missed approach climb is always considered single engine and can (and will) be a limiting factor.
The landing climb gradient is considered all engines and is generally never limiting.

[pineteam]

Terrain Performance or Departure Performance?
In the US, the A320 is certainly limited in some Altitude Constraints on SIDs. In fact, ORD just added a lateral half mile to its' DME/Alt requirements, and a heavy 321 on a hot day out of LAS will struggle above Green Dot....
Yes terrain performance. = ) Yeah Heavy A321 250kt won’t comply with some altitude constraints during departure.

[FlightDetent]

A) its not an opinion. It's reflective of the likelihood of CFIT.
B) The answer is -you fly the procedure for each scenario as defined by your Aircraft specific Company provided performance solution. If you stood by your word, and would only fly airlines who provide their pilots with a monkey read - monkey do scenarios for the discussed case, I reckon you would not travel very far.

A heavy A321 is when after the DER turn you are climbing AEO with 11,5 deg pitch on flaps 3 at 300 fpm, and start questioning your memory banks what exactly was the engine out attitude after takeoff. :(

[FlightDetent]

Thank you for the enlightenment :) ;) This answer my question... If you do follow the MAPr on -1 engine, be prepared to answer the question when will you accelerate and how to observe the TOGA engine limits. In this regard people who advocate a dedicated OEI procedure at all times are standing on the cleaned side of the street.
-

[Ondraayyy]

Hi,

when You do your calculations for dispatch landing performance You will realize that in those kind of scenarios the approach climb gradient will limit your MLW, therefore 2 options : 1) Your ops establish an alternative missed approach if feasible performance wise or 2) you decrease your LW to comply with the missed approach gradient.

I get it now, the key lies within the climb gradient... Thank you!

[compressor stall]

We do our performance calculation using Flysmart on Ipad and we have the engine out go around gradient displayed for awareness so we know if we can comply with the required climb gradient or if we must follow the EOSID.

Without checking, what is the default climb gradient shown in the Flysmart landing module (in flight)?

[pineteam]

Hi Compressor Stall,

it’s 2.5% by default.

[john_tullamarine]

Keep in mind that the typical miss terrain clearance analysis isn't run just by looking at a simple comparison of gradients. Usually, the miss starts higher and the analysis looks at what gradients and profile will still clear the terrain profile - ie the aircraft's clearance will decrease during the miss but not to the extent that things get exciting. OEI, a simple gradient comparison analysis generally is not going to be terribly useful for commercial operations.

Whether takoff or miss, using a simple gradient analysis, rather than a discrete obstacle approach to the problem, usually is too weight limiting.

[compressor stall]

Hi Compressor Stall,

it’s 2.5% by default.


Just checking - as the STD setting is 2.1%....

[MD83FO]

Qatar airways uses maximum temperatures that allow a single engine published missed approach below max landing weight published on jepp 10-7

When that is not available, the procedure is to use the maximum level of altitude (fly smart takeoff performance) to determine weather the missed approach altitude or the applicable MSA(whichever is lower) can be achieved within 10 minutes, if it is lower then you apply 10-7.

[Airmann]

This is my personal take, not authorized or anything.

An EOSID assumes the worst possible conditions at take off (i.e. high temperature, Max take off weight etc.). Therefore an EOSID can always be used as a missed approach with a single engine.

If you assume go around with a single engine at the time that results in the aircraft being at the lowest possible altitude i.e. in the flare with a bounce, then once you are airborne it is esentially as though you have rotated at the start of the runway. If the EOSID can cater for you taking off at the DER with single engine and the worst conditions it can cater for any condition similar or better than that. Just ensure acceleration is done at the same alt as you would do on single engine take off.

[FlightDetent]

Without checking, what is the default climb gradient shown in the Flysmart landing module (in flight)?
2.1 normal and 2.5 LVP ops. IIRC.

[compressor stall]

As I understand it, the default setting is 2.1%. You have to manually enter 2.5% for the LVP, as the App has no idea if it’s LVP or not.

There’s no way I can see to change this default in the back end either.

[john_tullamarine]

An EOSID assumes the worst possible conditions at take off (i.e. high temperature, Max take off weight etc.). Therefore an EOSID can always be used as a missed approach with a single engine.

Not quite the case. Configuration and configuration change, speed delta and height loss (?) / distance to get to a suitable comparison configuration and speed. Can get to be an involved analysis and, generally, not addressed in AFM data so it's back to basics and some simple flight test number work.

[FlightDetent]

As I understand it, the default setting is 2.1%. You have to manually enter 2.5% for the LVP, as the App has no idea if it’s LVP or not. That the 2.1 changes automatically to 2.5 when CAT II approach type is selected in the other box was without checking :), a memory from longer ago. The softair's explanation at the time was those were the regulatory (cs-25 or similar) figures for the aeroplane, unlike PANS-OPS values, hence it comes out of the factory that way. Pronto we changed both in the configuration file to 2.5 and set the calculation altitude at 1500 AAL with the help of PPM.

I only have access to fragments of the updated SW from a different source these days (back to RTOW charts, what a load of fun they are) and the one I have behaves differently - upon selecting CAT II the 2.1 remains and gets rejected as the entry filter is still set at 2.5. Whether or not these can still be pre-configured at the present version I have no clue.

https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/564x320/image1_43bcc71228cb007d08985cc4cfd682ff4df09f3e.png

[poldek77]

2.1 normal and 2.5 LVP ops. IIRC.

According to Doc 8168 Vol. 1 the number is 2.5 regardless of the type of approach.
Could you give any reference for this 2.1% (other than the App)?

6.1.7 Missed approach gradient
6.1.7.1 Normally procedures are based on a minimum missed approach climb gradient of 2.5 per cent. A gradient of 2 per cent may be used in the procedure construction if the necessary survey and safeguarding have been provided. With the approval of the appropriate authority, gradients of 3, 4 or 5 per cent may be used for aircraft whose climb performance permits an operational advantage to be thus obtained.
6.1.7.2 When a gradient other than 2.5 per cent is used, this is indicated on the instrument approach chart. In addition to the OCA/H for this gradient, the OCA/H applicable to the nominal gradient will also be shown.
6.1.7.3 Special conditions. It is emphasized that a missed approach procedure which is based on the nominal climb gradient of 2.5 per cent cannot be used by all aeroplanes when operating at or near maximum certificated gross mass and engine-out conditions. The operation of aeroplanes under these conditions needs special consideration at aerodromes which are critical due to obstacles on the missed approach area. This may result in a special procedure being established with a possible increase in the DA/H or MDA/H.

[FlightDetent]

poldek77 agreed, see my post #7. It's airworthiness not flight operations for the 2.1%.

EASA CS 25.121 Climb: one-engine inoperative
(d) Approach. In a configuration corresponding to the normal all-engines operating procedure [...]
(1) The steady gradient of climb may not be less than 2·1 % for two-engined aeroplanes [...], with
- (i) The critical engine inoperative, the remaining engines at the go-around power or thrust setting;
- (ii) The maximum landing weight;
- (iii) A climb speed established in connection with normal landing procedures, [...] and
- (iv) Landing gear retracted.

You make me go research things! :{ Oh well then, another file on the drive. (https://www.easa.europa.eu/document-library/certification-specifications/cs-25-amendment-23)

[compressor stall]

Flight Detent - my apologies - I forgot the CAT II button was there... we don't do them so it's a section I glaze over!!

[FlightDetent]

On second thought, we may had hacked the LPC.NG configuration files directly, as opposed to changing the setup via the admin module. Hope you find what you need, the value of 2.1 is of absolutely no use to operator staff and their crew.

[poldek77]

poldek77 agreed, see my post #7. It's airworthiness not flight operations for the 2.1%.

EASA CS 25.121 Climb: one-engine inoperative
(d) Approach. In a configuration corresponding to the normal all-engines operating procedure [...]
(1) The steady gradient of climb may not be less than 2·1 % for two-engined aeroplanes [...], with
- (i) The critical engine inoperative, the remaining engines at the go-around power or thrust setting;
- (ii) The maximum landing weight;
- (iii) A climb speed established in connection with normal landing procedures, [...] and
- (iv) Landing gear retracted.

You make me go research things! :{ Oh well then, another file on the drive. (https://www.easa.europa.eu/document-library/certification-specifications/cs-25-amendment-23)

Now it's clear for me - many thanks!

[compressor stall]

On second thought, we may had hacked the LPC.NG configuration files directly, as opposed to changing the setup via the admin module. Hope you find what you need, the value of 2.1 is of absolutely no use to operator staff and their crew.

Yes - I'll do some more digging, but when I set up Flysmart ca. 5 years ago changing the min 2.1% wasn't an admin option. It's not my area any more, but I'll have a nosey into the files and see if its changed.