View Full Version : Set Missed Approach Altitude (767/757/744)

8th Mar 2009, 07:19
I've just been told that the procedure for go-arounds for UAL 757/767's is ...

""Going Around"

-Press G/A switch, pitch for 11* ANU (767) or 12.5* (757)

"Positive Rate, Gear Up, Set missed approach altitude"

-Passing 400AFE, LNAV........ "

I've always been under the impression that aircraft system logic needs to see a higher altitude in the MCP (than aircraft altitude) before it will climb in GA mode (in a similar fashion to FLCH). Isn't setting the Missed Approach Altitude at GA a bit too late?

Company option?


8th Mar 2009, 08:17
in general the TOGA sets the pitch for the ap or pilot to aim for.

in a NPA for example, in Glf aircraft go missed, TOGA, and as the Alt preset can not be set until GA, then dial in the Missed alt.

So the Aircraft will climb, based on TOGA pitch until a alt is set.


8th Mar 2009, 09:11
G’day NSEU,

When flying an ILS I set the MAA when the G/S captures and when flying a NPA I set the MAA after the last altitude constraint before MDA.

(B767 Driver)

8th Mar 2009, 09:20
When you set the MAA depends on what kind of approach you are flying. Your info is obviously wrong because you always raise the flaps before the gear and that step was omitted completely.

Mach E Avelli
8th Mar 2009, 09:58
Non-type specific, but the way I teach it is:

For ILS approach, setting MAA at glideslope capture is OK because the aircraft will follow the slope all the way to the correct touchdown zone, even if it's only a cat 1 ILS. So even if you inadvertently bust minimums, if accurately flown, the aircraft probably won't hit anything too damaging. May wipe out a few lights etc, but it will be survivable.
Non-precision straight-in to the runway - as someone above mentions,you can set MAA after leaving the last limiting altitude as one option. Not one I favour, because you are losing some protection - on this type of approach it IS possible to hit the hard stuff if you get too low. However if you do leave the minimum set, be prepared to disconnect autopilot about 150 to 200 feet before minimum, to prevent the aircraft flaring to capture the altitude and thus de-stabilizing the flight path.
Circling approach - essential to leave the minimum set until it does capture on autopilot - that's what you want it to do to safely circle. Then set up the altitude alerter for missed approach in case of subsequent loss of visual reference.
The object of the exercise is try not to be too busy late on the approach, or during the early part of the missed approach, but at the same time not to throw away all the protections and warnings that the manufacturer has given you.
But as always, your own company SOP is the one you are supposed to follow. Regrettably some SOPs do force pilots to get more busy than they should have to be during approaches. The simpler the procedure, the more likely it is to be consistently performed when the weather conditions are bad or other things are going wrong.

11th Mar 2009, 05:50
Thanks, gents.

I just discovered that United Airlines set their MAA after pushing TOGA (autopilot coupled approach), so the list is correct in most respects.

This either means that aircraft of this type are capable of making a go-around (during an autopilot coupled approach) without a MAA dialled in or United have modified their aircraft to allow it. UAL seem to have a lot of non-standard procedures, with aircraft to match.

Actually, I was trying to look more at the aircraft logic side of things, rather than procedures. However, I was slightly concerned that if the person dialling in the MAA had slippery fingers and let go of the knob at the wrong altitude during go around, the aircraft might prematurely level off. Or, if the MAA was relatively low and the go-around was performed at a relatively high height, then the pilots may fly through the MAA (because they didn't set the MAA fast enough).


11th Mar 2009, 09:12
For Boeings it is standard to set MAA after GS capture as it will then be disregarded. On a GA, it is already set and waiting for you. I am chanting a mantra to myself- GA Flap 15 (or 20), pos climb, gear up, 400' set roll mode, look at what AA is, think what to do, tell ATC- we don't have to follow ALL that poxy GA procedure do we?- hustle for radar vectors straight around for another, don't forget ATO checklist, remember to breath, think about PA- they're such a bunch of wimps these days, they'll be screaming and throwing up and planning to report it in Prune!

It seems to work.

7th Apr 2009, 08:40
Now I'm curious

what is the procedure that UAL adopt for a SE GA? Still resetting MCP altitude after pushing the TOGA botton?

7th Apr 2009, 17:10
From a B744 perspective:
NSEU - as others have said it depends on the approach.

On the system logic side of things; In APP mode with G/S captured, the autopilot/s will follow the g/s down to the runway irrespective of the MCP set alt. When flying a NPA using VNAV, normally (ILS overlays are usually available for NDB approaches) system logic will commence at or slightly after the descent point (in any case before the FAF), thus resetting the MCP to MAA can be done before commencing final approach. If you are conducting a circling approach, you would obviously want to leave the MCP set alt at circling minima, as the level off is required. I find the policy of setting MAA in the go-around very interesting, and it certainly isn't policy where I am.

8th Apr 2009, 08:47
surely depends on the type of app. ILS/non ILS/circling!
but we are trying to include on the landing check list:

landing chk list - complete.

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