TOGA on 737ng
 

After pressing the TOGA buttons on TO and take off thrust is set.

What happens if they are pushed again?:confused:

1)with an assumed temp derate.

2)A fixed derate

and finaly

3) a combined derate.

Once the airplane has increased speed above 84 knots, THR HLD is active, so there is no physical restriction on the movement of the thrust levers - you can reposition as you like!

Cheers FD :uhoh:

IFF- good question. Had just this on take-off roll on a 747 at Orlando. After setting thrust and before Throttle Hold, we were concerned at the wall of weather ahead and local reports of windshear, so I hit the TOGA button again and got full power (it was lovely, 4 RB211s going up to full chat- glorious sound, and a noticeable surge on roll in a moderately heavy 747). I'm not sure whether it would still work after Throttle Hold, I think maybe not though as the Boeing 737 Flight Crew Ops Manual (11.32.3) states "if conditions are encountered where more thrust is required, the crew can manually aply full thrust." Remember, you are in Throttle Hold so you can do what you like with the throttles, and the automatics will take no further interest until ARM mode at 400'RA and 18 seconds from lift off (oh Heavens, I must get out more!)

PS I finished a 737 tech course yesterday (that's my excuse).

IFF,

Just as an addition to my last;
I'm assuming you are aware that when using derated power for takeoff, the Vmcg is calculated on the derated thrust setting, therefore that is to be considered the maximum thrust for that takeoff.
In the assumed temperature reduced thrust situation, the Vmcg is still calculated at the maximum thrust setting so therefore you can apply additional thrust as you like.

Cheers, FD :uhoh:

many thanks

As far as I can remember. Before thrust hold

1/ (I assume you mean assumed temp not derate). You get full take off thrust

2/ No change (you already have full thrust for that derate)

3/ You get full thrust for that derate

Do not derate and assume the temp, too much, not recomended. What happens when you push the button was discussed above.

Fly safe and land happy

NG

TOGA
 

after THR/HLD, nothing will happen. After takeoff and with gear up a second push will set GA THR.
cheers