Autothrottle problem

[tatin 98 0]

hi, my "problem" is not the autothrottle itself. next to the lights test switch, there is some sort of panel with three lights: A/P, A/T and FMC. The A/T is always flashing during approach, but especially when i select a new flap setting. EXAMPLE: i select flaps 1, then reduce my speed to the "number 1" that appears on the speed tape. Please, if i am making any mistake, correct me and i will thank you.

thanks in advance 

 

tatin 98

[hopskip 253]

Is it red or amber/yellow?

 

Red flashing means that the Autothrottle has been disconnected and you are in manual thrust, click the Autothrottle disconnect a second time to get rid of the flashing (or on the actual flashing light).

 

Amber/Yellow is some kind of mode disagree which I forget what it means. Maybe double check your autothrottle modes to make sure you are in the mode you think you are in.

[kevinh 409]

In this case, flashing amber means a speed error, the airspeed is not close to the bug setting.  More than 10 kts out on some Boeings, not sure about the NG. So when you dial in a new speed the thrust will reduce but airspeed doesn't respond immediately so the amber light flashes until speed is close to the bug setting.

[tatin 98 0]

OK guys, thanks. i thought i was making an error, because i watch videos of 737 ngx, and they dont have that light flashing. 

Is it red or amber/yellow?

 

Red flashing means that the Autothrottle has been disconnected and you are in manual thrust, click the Autothrottle disconnect a second time to get rid of the flashing (or on the actual flashing light).

 

Amber/Yellow is some kind of mode disagree which I forget what it means. Maybe double check your autothrottle modes to make sure you are in the mode you think you are in.

it is yellow.

[hopskip 253]

Indicates A/T airspeed error under following conditions...
Inflight & Flaps not up:
Airspeed differs from commanded value by +10 or -5kts and is not approaching command value.

 

Ie: if you are at 200 knots and the speed is set to 210kts and you are slowing down.

 

I think it can also happen if you are in or fast approaching the 'yellow' area of the speedtape (either too fast or too slow for the selected flap).