Non standard Go around 737

[Olendirk]

Guys, how would you solve such situations following with the autopilot active:

1. On the glide, 2300agl, runway blocked, go around, ap engaged

2.on the glide, just intercepted the glide, go aorund, runway blocked, ap engaged


3.on the ils, gear down flaps 15, ap engaged, app takes you out of sequence with a 90° right turn, what to do


any nice hints concerning such non std situations, i think we dont do training so often on them!


OD

[Shiny side down]

Why is the runway blocked?
Can you confirm what scanario 3 means?

Are these sim exercises that you have had? Or real encounters?

I wouldn't get too caught up in thinking about them as non standard situations. Simply break them down into go-arounds

On the 737, the 2 engine go-around function requires
1. a decision to go-around.
2. Use of toga. 1 press = a more gentle climb, 2nd press gives you the full performance, which you probably won't need in most cases.
3. A call- 'Go around-flap15'

When you hit toga, the go around sequence has begun, and because you are single channel, you won't have the autopilot. Fly the LNAV go around procedure.

Get the positive rate- gear up.
Flaps will be bugged, and retracted as you pass the bug (speed tape)
(If you are already at flap15, make sure the other bloke/person doesn't give you something less useful)

Make sure that you always, ALWAYS, set the go around altitude as soon as you capture the glideslope.

I'm not entirely sure what your scanario 3 means. A little more information would be useful. Do you mean that the aircraft is suddenly turning with the ILS captured?

[cirr737]

I think in all of your cases reverting to CWS and the reengaging the A/P with LVL-Change and increasing the speed while cleaning up would do a better job than hitting TO/GA because you are not approaching your level-off altitude like a space-shuttle.

However it depends... if you are already fully configured or at a terrain critical Airport I would definetly consider the use of TO/GA

[Olendirk]

yeah right thats what i thought, to use lvl chg and get up there,can i get out of the loc GS programm with just pressing the lvlchg button and deselect the app mode?thought that wont work!

cheerio

OD

[cirr737]

No it wont... you have to revert to CWS first - do it preferably with the A/P engage paddles or by detuning the ILS.... or just fly it basic manual...

[Shiny side down]

A word of caution though. A flurry of hands attempting to select something other than a go-around can result in a continued descent, without any meaningful monitoring, and no clear plan of action.

If I read this right, Olendirk has recently finished the type rating/training. So a level of abnormal procedure and unfamiliar procedure, applied to a an early go around, could result in anything other than a normal go around.

I'm not saying it's wrong. But you brief to do an approach. And you brief to do a go-around if the approach doesn't work. Anything else is potentially making it up as you go along. Beware of 2 different plans happening at the same time.

I base that on a sim event!

[despegue]

Olendirk,

Follow the normal Go-around procedures and callouts. KISS (keep it simple stupid). This will avoid confusion.

One thing though, but a very important one...
As "Shiny side down" said, don't wait to set missed app. alt. in the window after glideslope capture, but be always aware that if you are light and the level-off alt. is close to your present altitude (in your situations quite possible),pressing TOGA will give far too much thrust and you risk overshooting your altitude AND a possible unstable flight condition when realising and trying to recover... Keep this in mind please, I can't stress that enough. Never blindly push TOGA without being prepared for the changes in flight-path it will give.

[Jonny Foreigner]

You seem to be are asking how to escape from VOR/LOC capture and G/S capture without landing? I have done the following in the sim...... It works.

Think you will find that TO/GA is only available below 2000' RA.
In all of those senarios described I agree with Despegue. Keep it simple.

As soon as you are G/S established set the G/A target.
If you need to go around before you are below 2000' RA but FULLY ESTABLISHED, deselect the ILS frequency (back to Auto), then I would suggest V/S to G/A target with heading select! The auto pilot WILL remain engaged, as you are not using TO/GA. By deselecting the ILS you are essentially blinding the aircraft, preventing it doing what you asked it to do,( fly the ILS).

Hope this helps.

[Olendirk]

just to make sure that i understand:when i put the ils away from both receivers, what happens to the ap? does it revert automatically to CWS?

cheerio

[cirr737]

Yes it will - actually it is sufficient to remove the ILS from the active A/Ps side

However: This is N O T recommended by Boeing - Boeing recommends paddles to CWS and then back to CMD or disconnect and re-engage (thats how I do it most of the time when I need to get rid of approach mode, for example in a swing over, and dont feel like manually flying it down)

[Jonny Foreigner]

To be honest, I did this exercise about two years ago so I'm not certain the following is entirely accurate.

By deselecting the ILS frequencies and preventing reception of the signal the A/P basically gives up and hands control back to you in CWS. As such pitch and roll are yours! The aircraft in all probability will then deviate from the desired ILS profile.

This event should obviously only be momentary. You have a target G/A altitude set in the MCP (higher or lower than present altitude makes no difference). So as soon as you select a new pitch (LVL CHG or V/S) and roll (HDG) mode on the MCP full A/P will re engage and fly in your chosen mode to the selected targets.

If you select TO/GA below 2000' RA single channel approach it's a different game entirely. You then have to start exercising those silky flying skills!:O

Hope that is of help.

[gas-chamber]

Call me a Luddite if you will, but what is wrong with disconnecting the A/P and A/T and hand-flying it to the assigned heading and altitude, calling for flap, gear, altitude select, heading bugs, course bars and navaids as required? Make that co-pilot work! Look after the thrust yourself, as you won't need huge amounts for the small altitude change likely from above 2000 feet to typical missed approach altitude. Re-engage automatics when all settled down.

[Blip]

Just so that people who don't fly the B737 understand, once you have localizer and glide slope capture in Approach mode, you can't simply select a different pitch or roll mode.

From the B737-400 Operations Manual:


After VOR/LOC and G/S are both captured, the APP mode can be exited by:
• pressing a TO/GA switch
• disengaging A/P and turning off both F/D switches
• retuning a VHF NAV receiver.


gas chamber, I suppose there is nothing wrong with that except to say that it doesn't sound like you could increase the workload even if you wanted to.

Make that co-pilot work!

Sounds like you wanted to! :)