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gibas
31st Oct 2008, 11:16
Hi guys!

Have seen lots of discussion about this matter along my career in different operators and fleets.
Regarding a OEI Go Around at which altitude do you level off for acceleration?
Let's divide it into two parts:
Legal Part.
Taking a look at old Doc 8168 it states (more or less) that Missed approach procedures assume a 2.1% (2.5% Low Vis) gradient obsct clearence and an acceleration segment at a min alt of 820ft AGL and 6NM max. for clean up followed by a 1% for en route climb.
Those procedures that do not meet this, a note "climb to xxx feet prior to level accel." should be contained in the miss app procd.
Taking a look at the Jepp charts in Europe, surprisingly I have just seen this note published in French Aerodromes only.(Depends on national AIP?)

Operational part:
What do we pilots (operators) do in real life?
I've seen operators that take a fixed value e.g the FMS default value (1500 ft) for acc alt, others take the final Missed app proc alt, others perform an Eng Out SID!? (which never is included in the briefing assuming an Eng fail during the GoAround) and there's the big discussion for the eternal "what if" guys: what if you go around below minima (balked ldg).

I've seen many high experienced white elefeants speculating with guesses like: "well it depends on the scenario, obstacles,IMC, etc.)
I'm not looking for that response :=, because I have it at home sharing a beer (After 5 beers every pilot can do single engine aerobatics, we all know, I'm included)

Can anyone out there bring some light to this humble aviation servant?

Thanks in advance.

error_401
31st Oct 2008, 11:32
Sorry,

but "No, I can't either".
I've been posing the same question multiple times to all sort or pilots be it technical, procedure guys etc.

At the end of the day we are left with this decision to be taken the day it happens - I try to stay safe.

better high then low, better fast than slow.

then it comes to the details assuming a CAT I (OEI) Minimum and going around at 200 feet. How long does your gear take to get up? And where are you once it is up and the flaps are in by that one notch?

I think it really boils down to what the situation is. When going around at MLW with a 4 Eng in hot and high you may have the flaps at go-around position and the gear up when reaching 860'.

Try that in a high performance bizzjet. By the time the gear is up, you shoot through 1'500 feet at 3'000 feet per minute...

I try to judge where, when loosing an engine in the approach (go-around), I may be able to reach the standard missed approach track and especially vertical profile.

Does it help with your question? Discussion is opened... ;)

Rainboe
31st Oct 2008, 12:28
Normal procedure with my 2 operators is clean up at 1000'R normal or OEI unless different procedure specified in the go-around instructions. Taking the worst case, OEI go-around from baulked landing, Flap raised to standard go-around position (maybe 5 seconds), gear raised. Depending on type, small acceleration and raising of flap to special OEI setting to ensure adequate climb. If this still would not give you correct climb angle, then your performance max lndng weight would have been adjusted down. All you have to do is concentrate on flying the correct procedure knowing that someone has done the paperwork beforehand to ensure you will meet climb requirements! The proc you found states a minimum clean up of 820' and 6 nms, all well within design capabilities. So what you do in real life is 'follow instructions unless different procedure specified'! The 'FMS default altitude' is whatever your operator suggests as a default. Many airlines use 1000'R

Pilot Pete
31st Oct 2008, 16:38
All you have to do is concentrate on flying the correct procedure knowing that someone has done the paperwork beforehand to ensure you will meet climb requirements In the ideal world.

Our procedures changed a few years ago precicely because this wasn't the case. There is no level segment accelleration in a missed approach procedure, so single engine accelleration in level flight compromises this.

We now calculate the lower of 25nm MSA, Missed Approach Level Off Altitude or Minimum Holding Altitude (if the missed approach terminates at a hold) and use this for our level accelleration.

PP

ACMS
31st Oct 2008, 23:23
Well in that case your company should publish an engine inop missed approach escape proceedure for you to follow.

It will probably be similar to the engine inop T/O escape proceedure. ( for the same rwy )

john_tullamarine
1st Nov 2008, 00:01
A prudent operator will do something along the following lines ..

(a) generate a generic OEI miss procedure which includes consideration of reconfiguration performance/distance and acceleration segment similar to the takeoff case ... and determine the effective net obstacle profile which such a procedure can overlay

(b) assess all runways within the area of operations to determine if each runway can tolerate the generic procedure

(c) run specific runway miss analyses for those runways which can't fit within (a)

.. if a pilot, operating without such support, has to do the sums him/herself, then a more pragmatic approach is to raise the minimum altitude to suit a grossly simplified miss .. lower than that and you are committed to the landing. The more time/data available, considering pilot knowledge and performance competence, the smaller the margin of conservatism might be.

gibas
1st Nov 2008, 05:33
Thank You, John!

Your answer helps a lot and agrees with what I think it has to be done by a Responsible operator.
That's the only difference: You call it Prudence and I call it Responsability.

If companies would train crews in a responsible way, then aviation would be much safer.
Keep it simple and safe and aviators would fly it.

My experience is that unfortunately there are so few companies that comply with that for several reasons:
1.- Many because the guys in charge (Training and Ops Postholders) are not capable because of lack of knowledge.
2.- Many guys who "hold the post" (definition of postholder) know how to, but they don't share their Jedi knowlege with the rest of mortals, because mortals should know that.
3.- Most postholders "hold the post" just for the money and don't listen to TRI's and TRE's, as it is better to leave everything as is, because it has worked until now.
4.- The more confused crews are and the less defined the operation is, the easier for companies to blame on pilots if s:mad:t happens.

Sorry guys, I know this is a technical forum....
But I couldn't resist, now I feel much better.

Cheers.

BOAC
1st Nov 2008, 08:51
I think Gibas's 4 points should be essential reading for post holders. In between the 'ideal world' of JT "A prudent operator will do something along the following lines" and the rose-tinted Rainboe's "knowing that someone has done the paperwork beforehand to ensure you will meet climb requirements!" lie a raft of companies with less than perfect performance assessments. We all know that some companies do not follow EUOPS requirements in fully surveying OEI take-off routes. The chances of a thorough look at OEI g/rounds are slimmer. I know of one OEI g/a in a large British airline that had not been thought about. As gibas says, it is encumbent on crew to 'close the gap' and to be aware of any possible obstacle/s which may have been overlooked by others. Obviously the lower the g/a altitude the closer one gets to the OEI take-off problems until the 'baulked landing' g/a mentioned by gibas becomes a significant consideration, as in SZG or MRS.

Che Guevara
1st Nov 2008, 09:32
GIBAS

Regarding a OEI Go Around at which altitude do you level off for acceleration?


Our company has an 'emergency turn' for all the airports that we operate into if there is an obstacle problem for OEI. We are required to brief them for all T/O and LDGs if they are published. If we fly the emergency turn then we accelerate (level off) when all turns are complete (if there are more than one specified) or when we get to the MSA, whichever comes earliest. If there is no emergency turn required, we fly runway track and accelerate at 1500' AGL, declare a MAYDAY and advise of our intentions.

We operate 320/330/340s and the emergency turn procedure is valid for all types.

Cheers

SIDSTAR
2nd Nov 2008, 07:33
BOAC,

Absolutely correct. EUOPS requires the Operator to provide crews with a safe path back to a point from which a landing can be made. In the past we all had Emergency Turns only where there were obstacles in the takeoff flightpath that couldn't be cleared with the normal straight-ahead acceleration (altitudes varied with manufacturer and airlines). Then we were left on our own at 1500 ft with the a/c clean.

Now we are better protected and the same requirements of a safe path applies to the G/A. In our company we brief the Emergency Turn procedure for both takeoff and landing and include it in the FMGS (A320) secondary flight plan and/or Rad Nav page.

It is slightly more workload for the crew but it means we're protected. Get your company to do the same or get your performance done by an EUOPS company.

Flambards
2nd Nov 2008, 10:44
Regarding the go-round below minima, the EO SID designers expect you to fly the EOSID if you suffer a go-round below minima.

Above minima then the SID is the route you fly. (subject to the standard or additional restrictions on the plate)

EO acceleration altitude is subject to same rules normally used for each case. i.e SID or EO on takeoff.

All engine go-round is a different matter, as long as you make the noise abatement rules , the company SOPs, FCOM limits and climb gradients - you do what ever you want!