A320: min time for FDs to be off ?
After landing flows / "cycle" the FDs
I seem to recalll hearing, or reading, that both FDs need to BOTH be off for like 5 seconds or they will not reset properly. Where in the FCOM, or maybe Airbus bulletin, is this published ? Thank You |
It's not and don't think it ever was. It's an invented procedure that goes back to the old days when the FMGC/MCDU was running on older hardware and would timeout/crash. It was resolved by some pilots switching of the FDs as they thought that would place less demand on the computers and reduce the chance of a timeout. Some airlines have developed an SOP to switch off. Beats me.
|
Never heard of it, but I have noticed that some of the most senior A320 pilots in my company switch them off in their PM after landing flow.
|
Originally Posted by enzino
(Post 11474638)
Never heard of it, but I have noticed that some of the most senior A320 pilots in my company switch them off in their PM after landing flow.
|
FDs are always ON regardless of the position of the FD PB.... You are only "Removing them from view" by the action of PB....
|
It's a hangover from the first-generation FMGS, where cycling the flight directors on the ground reset the FMS for the next flight. Nowadays (well, since the early 2000s really) this happens automatically once you leave the runway after landing.
|
Originally Posted by 321XLR
(Post 11474526)
After landing flows / "cycle" the FDs
I seem to recalll hearing, or reading, that both FDs need to BOTH be off for like 5 seconds or they will not reset properly. Where in the FCOM, or maybe Airbus bulletin, is this published ? Thank You switching FDs OFF in the after landing flow is a homemade non standard procedure that is often brought in by people with previous experience on other types such as the 737 or the MD80. Some airlines might add it in their after landing flow for some reasons but it is an unnecessary action. Standard Airbus SOPs do not ask for FDs OFF during the after landing and during the Cockpit Preparation flow the wording is "FD....Check ON | PF-PM" meaning that it is supposed to be already on and you are checking the correct status. |
My company resets the FD after each landing. Then again, we try to fly it the same we we flew the DC9.
|
Originally Posted by Rocket3837
(Post 11474750)
FDs are always ON regardless of the position of the FD PB.... You are only "Removing them from view" by the action of PB....
|
Originally Posted by giggitygiggity
(Post 11475105)
Removing the FDs has other important functions such as forcing thrust to go into SPEED mode.
Further, you can engage the AP while the FDs are already OFF..... Thanks |
All times are GMT. The time now is 14:40. |
Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.