B777 TOGA GA with A/T off

[extricate]

Hi,

FCTM talks about pressing TOGA for a GA with A/P or manual flying, but how about with A/T off?

Will the TOGA still work? or we have to set thrust ourselves and press TOGA for F/D guidance?

Any reference will be good.

Thanks

[jackcarls0n]

That is a very good question. It would be rare that the A/T would be set to off, but if it is- The Lateral and Vertical mode will go to TOGA/TOGA, the speed mode will be blank, and the throttles have to be manually moved. The engines will not be commanded to GA thrust automatically, only GA reference thrust displayed on the Engine Primary Display.
Pretty much like flying an airplane without auto-throttle.

[Jwscud]

With the AT disconnected or the AT Arm switches set to off?

In the former case, a push of TOGA will give THR|TOGA|TOGA

In the latter, you are full Manual thrust no matter what.

FCOM 4.10.4 for AT ARM Switch description.

[extricate]

The siutation is A/T arm switches on but A/T disconnected

[STBYRUD]

If that is the situation then you have full TO/GA functionality. Disconnecting the A/T with the throttle switches keeps them armed with all implications, similar to when one would deselect SPD in a 737. Sidebar: I would have expected Boeing to change their recommended SOPs to match the other Boeings in use after the Asiana and Emirates accidents, disconnecting the autothrottles for manual flight - especially because the TO/GA functionality would still be there if you needed it...

[Jwscud]

There is a reason many trainers are anal about the words you use - it is very important to distinguish between the disconnect triggered by the thrust lever push buttons and the MCP arm switches.

This is particularly the case in the Airspeed Unreliable checklist as if you get the memory items wrong and just use the push buttons the autothrottle may re-engage in odd ways prompted by the erroneous airspeed readings.

[extricate]

Thanks, understood!