INOP SYS - Autopilot and Flight Directors

Disclaimer: 

▪︎This content is Not an official document and does not represent the views of Airbus or any other aviation authority.

▪︎The information provided may be incorrect or misinterpreted and should not be relied upon for decision-making. 

▪︎Always refer to official documents and consult with a qualified aviation professional before making any decisions based on the information provided in this blog post.

▪︎The information provided in this blog post is based on personal study and review.

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ECAM INOP SYSTEM - AP 1+2 

In an Airbus ECAM procedure, one of the status pages on the System Display (SD) shows a list of INOP systems. 

If the Autopilot 1+2 is listed in the INOP systems, it may be tempting to think that flying manually is the only restriction. 

However, it's important to note that losing the autopilot may also affect other systems and components, such as the Flight Director (FD) , which may require additional procedures to ensure safe flight operations.

 

If the flight director is inoperative, it does not say "FD" on the inop Sys.

In the Airbus ECAM procedure, if the Autothrust system is inoperative, it will be displayed as "A/THR" on the INOP systems list on the SD page. However, if the Flight Director (FD) system is inoperative, it does not be specifically listed as "FD" on the INOP systems list.

 

FD inoperative Indication 

Does "AP 1+2"indication necessary mean the failure of the Flight directors?

In order to check if the Flight directors are working or not, we have to check PFD. 

If the guidance orders are not available while the FD is engaged, a FD flag appears on the PFD and the FD bars disappear.

 

RED FD indication on PFD - Appears if both FMGCs fail, or if both FDs are disengaged and the FD pb is ON and the attitude is valid.

 

and We should not rely solely on the FD bar lights to determine the status of the Flight Directors (FDs). we can press the FD pushbuttons on the FCU to check if they are working and if the lights on the FD pushbuttons come on.

The FD lights being off did not always indicate that the FDs were not operational. I am not entirely sure, but in some cases, such as when the electronic system is in AIRCRAFT ESS BUS SHED status in a Simulator (A/THR channel 1+2 fault), the FD bars may still be working even though the light on the FD pushbutton is not on.

 

 so it should be "FD engagement status on PFD" that we should look at. 

FD engagement status on PFD

FD and RNAV

After determining that Autopilot 1+2 is inoperative, we may also find that the Flight Director (FD) system is not functioning. In such a scenario, certain RNAV procedures may not be available, such as the RNAV 1 approach that requires the FD to be in NAV mode. If the FD is inoperative, we may not be able to accept RNAV 1 arrivals or RNAV approaches.

 

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Disclaimer: 

▪︎This content is Not an official document and does not represent the views of Airbus or any other aviation authority.

▪︎The information provided may be incorrect or misinterpreted and should not be relied upon for decision-making. 

▪︎Always refer to official documents and consult with a qualified aviation professional before making any decisions based on the information provided in this blog post.

▪︎The information provided in this blog post is based on personal study and review.