A320 Go Around Engagement Conditions with Honeywell FMGC 1A Update

[Easy226]

Most of the aircraft at the company I fly for have had FMGC release 1A installed however I have noticed in the FCOM that the engagement conditions for NAV mode are not consistent with this update. It states on the later models that NAV mode engages automatically :

'during a go-around when the aircraft is above 100ft RA and within the capture zone for the active flight plan leg unless HDG/TRK preset'

So if I fly an older aircraft in the fleet with the FMGC upgrade and go-around NAV mode will not engage/arm however on a newer one it will. Does anyone out there know why this is the case. Seeing as it is a flight guidance update I would think all would engage/arm nav during a go around?

Cheers

[Check Airman]

Not an Airbus pilot, but it seems that you've answered your question. You said that the newer, updated planes will engage NAV automatically. Perhaps they just haven't updated the older ones yet?

[Zippy Monster]

Check Airman,

Perhaps they just haven't updated the older ones yet?

What he means is, the FMGC Step 1A upgrade has been installed across pretty much the whole fleet, but the automatic engagement of NAV mode in a G/A is still dependent on the age of the aircraft (i.e. it will do it on newer MSNs but won't on older ones, even with the same FMGC software installed.)

For what it's worth, from the OP's username and description I believe I also fly the same fleet and no, I don't know either. I presume it's something to do with the hardware, of which a upgraded/modified version exists on the latest models and which won't have been upgraded on older models even though the FMGC software has been.

[Easy226]

Thanks for the quick replies. I tried to look into the fact that it could be on the aircraft which have the new green V/DEV indication (as opposed to magenta) however it turns out that this is due to a new DMC software standard. You never know though, with the Airbus maybe this DMC software is linked to the flight guidance (or vice versa) in some obscure way....

[BlackandBrown]

NAV blue will only happen on a Go Around on aircraft delivered from the factory with Step 1A. All aircraft UPGRADED (I.e. not brand new delivered with) with Step 1A will not automatically arm NAV. Why? I don't know but there's your answer. And that isn't my guessing or presumption - it's feedback from Airbus.

[Easy226]

Thanks B&B

[FlightPathOBN]

There are several variants of the 1A 'update', H1, H2, etc.

Within each update, there are options of 'mods', 38778, 39779, etc

Dependent on installed equipment, other updates, mods, and certifications...

The 1A H2 mod has the issue with fuel predictions on many A320's, so perhaps the issue you have mentioned is another bug, awaiting the new FMS version.....

[manuel ortiz]

FMS upgraded to 1A standard is just part of it.

In order to have automatic NAV engagement for GA (which is required by EASA for RNP below .3) one needs to have the FIS also upgraded and this last is what we don´t see done often.

[Rashid Bacon]

There are 2 components required to generate the auto NAV.

1. FMGS R1A
2. Latest version of EIS step 8 (think it's 8.3 but could be wrong)

Very old aircraft may also have issues with DMC/DU etc etc, so I am not sure whether the R1A mod is available for all MSN's without further pre update mods.

[Down Three Greens]

FMS REV 1A plus

-The Flight Guidance (FG) I11 Standard (Mod. 37252 or 37311) on aircraft that have IAE or PW engines, or
-The FG C12 Standard (Mod. 37934 or 37935) on aircraft that have CFM engines.

[Easy226]

Thanks a lot for the relies with this. So from what down three greens says in the last post, the step 1A upgrade only updates the flight management section of the FMGC and the flight guidance software needs to be updated for the automatic NAV engagement on go around (as well as EIS to 8/8.3).

[mono]

The upgrade to FMGC release 1A is software only.

The upgrade to Automatic Nav Engagement at Go Around needs to be activated by pin programming.

Most likely the older aircraft in your fleet while thay have had the software addition, have not had the wiring modifications carried out. No doubt, as the aircraft go into the hangar for checks these mods will be done.