View Full Version : 737 Classic deselecting approach mode
Scottie
15th Jul 2005, 10:41
Just doing a bit or revision at the moment on the 737 classic.
Once approach mode is engaged and the lights are out there are a number of ways of disengaging the mode.
One of them is by pressing the TOGA switch.
Since TOGA guidance is only available below 2,000ft RA is the TOGA switch activated at 2,000ft RA or will it allow you to disengage APPROACH mode above that?
Having never tried it yet I'm curious, will give it a go next time I'm flying :D
will it allow you to disengage APPROACH mode above that?You will have to disengage the A/P and turn off the Flight Director.
nimrod42
15th Jul 2005, 23:28
easiest way is to de-tune the ILS then you default into hdg!!
john_tullamarine
16th Jul 2005, 00:10
.. while not looking at the reason for wanting to disengage APP - and here it appears a simple how-does-the-system-work thing - would you REALLY want to tune the ILS off frequency during an approach - unless the intention was to abandon the approach ?
One could set oneself up for embarrassment if the intention was to continue ?
Instead of really changing the frequency, just push on the AUTO MAN pb...
The frequency is still there...;)
I think 'Scottie's' question was will TOGA disengage the a/p above 2000'? A/T G/A is certainly not available. I cannot answer the question for certain. I do not think I have ever done it, but I think TR4A is correct.
robtherower
16th Jul 2005, 18:18
Pressing toga above 1500' radio (dual channel) will cause a/p disconnect because auto goaround is not available. FD will then give TOGA commands, MCP speed window will be blank and flap speed bugged.
(I think!)
nimrod42
17th Jul 2005, 16:58
By de-tuning the ILS I was intending this for the NG series - so I should have read the question but flicking it to auto will have the same effect. Flick the changeover button, FD defaults and then you can select the ILS freq again. Obviously this would only be recommended as per the question when above 2000' when a TOGA go-around is not available. I agree that by deselecting the AP and turning off the FD's has the same effect but its a lot of faff.
I tried today in a 300 in every phase of flight (climb, cruise, descent, approach): the TOGA pbs are totally dead above 2000ft RA.
Absolutely nothing happens above that altitude.