Use of TOGA button

[Groundbased]

Quick question about use of the TOGA button on take off.

Does pressing the button set T/O thrust as per the FMC or do you manually set thrust and only engage TOGA after commencing the take off roll. Alternatively is manual thrust setting used during take off and automatics only engaged after rotation.

Cheers

GB

[classic crew]

On the B747-400 our procedure is to push the thrust levers up to about 70% to ensure that all the engines spool up together. Then we push the TOGA button.

If we are below 50 knots and the flaps are out of up (which they need to be for take off) pushing the TOGA switch activates the autothrottle in THR REF mode at reference thrust limit selected on THRUST LIMIT page (on preflight) and displayed on the upper EICAS.

It also updates the FMC position to runway landing threshold if the GPS updating is not active.

However, if we push the TOGA switch after 50 knots and below 400 altitude the autothrottle will not activate!! I'm sure you can work out what that does for the workload on the runway.

I hope that helps

[mono]

TOGA

Push to activate a go around if established on the approach

Push after advancing throttles to between 60/70% for take off thrust (or flex/reduced thrust)

This is the case for most boeings with A/T fitted.