A/T Disconnect after Engine Start B777
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Join Date: Feb 2018
Location: Frankfurt
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A/T Disconnect after Engine Start B777
Hi,
I (Aircraft Maintenance Tech) recently had a crew complaining that they had an "Autothrottle Disc" Amber Eicas Message after Engine Start. (Autothrottle Arm switches where armed before. The aircraft had 1h ground time without shutting off power.)
Question to the B777 Pilots: During final approach could it be that you sometimes land with A/T disconnected and only hit the disconnect button once. Leaving the Status Message active? Then park it and shutdown normally. ( Could it be that on Engine shutdown the Eicas Message disappears and then comes back after Engine Start because the disconnect button was only hit once?)
To all its just my theory. It might be wrong. (Not a pilot) Just want to understand what is going on since out of my perspective there was no "White" Status Message in the lower Eicas nor any fault code so I think the A/T System is 100% okay.
Could some last minute change in the Runway direction / V-Speeds) while LNAV and VNAV already been armed during preflight cause the A/T to disconnect after engine start?
Thanks for your support!
best regards,
F.
I (Aircraft Maintenance Tech) recently had a crew complaining that they had an "Autothrottle Disc" Amber Eicas Message after Engine Start. (Autothrottle Arm switches where armed before. The aircraft had 1h ground time without shutting off power.)
Question to the B777 Pilots: During final approach could it be that you sometimes land with A/T disconnected and only hit the disconnect button once. Leaving the Status Message active? Then park it and shutdown normally. ( Could it be that on Engine shutdown the Eicas Message disappears and then comes back after Engine Start because the disconnect button was only hit once?)
To all its just my theory. It might be wrong. (Not a pilot) Just want to understand what is going on since out of my perspective there was no "White" Status Message in the lower Eicas nor any fault code so I think the A/T System is 100% okay.
Could some last minute change in the Runway direction / V-Speeds) while LNAV and VNAV already been armed during preflight cause the A/T to disconnect after engine start?
Thanks for your support!
best regards,
F.
B777 always land with A/T ON.
The reality is B777 electric system no break power transfer is not as good as it claims especially on older aircrafts. I have seen displays flicker, CDU momentarary blanks, fuel pump gets knock off etc during electrical power transfer during engine start.
So a A/T EICAS message after engine start is not inconceivable.
The reality is B777 electric system no break power transfer is not as good as it claims especially on older aircrafts. I have seen displays flicker, CDU momentarary blanks, fuel pump gets knock off etc during electrical power transfer during engine start.
So a A/T EICAS message after engine start is not inconceivable.
