Greetings, Team

Our lovely FMGCS have many function, also act as SUPER-COMPUTER for Pilots. But seems it misses some point.

1. FMGCS CREATING WAYPOINT

FMGCS known is able to create waypoints whenever is needed to help either targeting route or to "guard" some altitude. Directly to the FPLN Page or STORED WAYPOINT. I am flying SVO-AMS today, I can't help but notice that it having some problem, like 2 samples below:

• Sample 1: On FPLN Page is not able to create "Place-Bearing/Place-Bearing" Waypoint which identifies as PBX##, but whenever I tried to insert it on PILOT STORED WAYPOINTS, it goes funny 😂

I try inserting "ISENG" Waypoint which consist of SPL-020/FRO-350 which like this: but stored like this ===>

it should showing the preset P-B/P-B (or in PBD, it should show the P/B/D)

But, what makes it even funnier, it shown like this on FPLN Page ====> waaayyy too far from the planned waypoint 😂

• Sample 2: The "Place/Distance" which shown as PD## also need correction, from Waypoint ARTIP to SPL to make ARTIP/6 or SPL/-25 which a place along the route in between, but somehow it is showing this:
  

i put it AFTER ARTIP waypoint but somehow it placed AFTER SPL and not along the route, it also makes a different Bearing than the preset.
I notice this is also happening on A350, but I forgot to tell you about this.

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2. FMGCS PROBLEM DURING DESCEND-TO-APPROACH PHASE AND AFTER-GO-AROUND-TO-RE-APPROACH PHASE

• Descend to Approach Phase

During descend phase, FCTM said that FMGCS calculates Descend Profile AT 2.5^Degrees Glide Path and with decelaration of 100feet/second on Level Flight or may less during deceleration (Rule of Thumb: 1,000 feet/10 Nm on Level Flight OR 2,000-2,500 feet/10 Nm in case of decelerating, with Speed of 10 Knots/Nm on Level Flight or around 20 kt/Nm during deceleration)

ICAO Doc 4444 stating that Speed should be 250 kt below 10 000 feet, and speed 220-210 kt below 5 000 - 6 000 feet at TMA (Around 30-25 Nm from the Airport), and most of airport now are doing speed 180 kt between 12 Nm to 8 Nm and 160 kt from 8 Nm to 4 Nm. Then doing VApp until landing.

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From what I notice from IniBuilds (A330/A340A/A350/A380), DECEL Pseudo-Waypoint is incorrectly simulated. Previously, FCTM-NOR-SOP stating that DECEL Pseudo-Waypoint is around 10-15Nm from Runway Threshold and it may goes further back if there's a speed constraint selected either on IAF, IF, or FAF to target speed around VApp at runway (IF NO SPEED CONSTRAINT, and may way further back if there is Speed Constraint on selected waypoint) but somehow actual Airbus' FMGCS doing Landing Flaps Config AT FAF instead of doing decelerated approach which stabilized at 1,000 ft. That is why I notice ALL IniBuilds Aircraft doesn't simulate the Decel Pseudo-Waypoint at FMGCS correctly.

For Example, I set speed on IAF (which PANS-ATM state around 10-15 Nm) at 180 kt, suddenly the Decel Pseudo-Waypoint moved forward towards FAF. And even worst at some High Altitude Approach (e.g LTFM which comes from 5,000 feet). See picture down below.

<<=== Both Pictures showing LTFM ILS Z Runway 35R

Actual Airbus FMGCS will move Decel P/W further back from IAF to compensate speed deceleration from Speed Control Constraint (250ktbelowFL100 or High Speed Descend) to GDot (which targeted by Magenta Dot) then targeting deceleration from GDot to IAF Selected Speed Constraint by Decel P/W.

So I can say that this is incorrectly simulated.

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• Missed Approach to Re-Approach Phase

I notice that every time I simulates Missed Approach, the Cruise Altitude is stayed on previous Target Cruise Altitude (FL350/FL390 or whatever previous Cruise Flight Phase selected). If I selected any Altitude, suddenly the speed goes >300 knots AFTER I re-direct to some waypoints and the rest of calculation of Magenta Dot, and Decel P/W IS GONE. But some cases, the Magenta Dot and Decel P/W is there but the FMGCS doesn't comply with that restriction and maintaining speed >300 knot even though I already preset 250/FL100 (or 220/FL050) and selected target speed or ATC-Managed Speed.

This also happening on A330/A340/A350, not specific on A380 Only.

Also, during the re-approach, the VSD on A350/A380 are showing like this ==> Imagine if you are flying RNAV/RNP Approach with this 😂

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3. FMGCS Keyboard Function

if I want to insert "-" or "+" on CDU using Keyboard Function, this can not be inserted on CDU to make anything. But it is normal if I am using the CDU Keyboard.

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If you guys can make corrections about this on any update, that would be great.

Thank you very much. Cheers.

HaveASafeFlight!

Edited Saturday at 12:59 PM5 days by OxkyGThaib

Thanks for your detailed report.

I will pass this along to the team for further review and clarification.

Thanks again!

On 9/20/2026 at 5:06 PM, iniKyle said:

Thanks for your detailed report.

I will pass this along to the team for further review and clarification.

Thanks again!

Just small information, @iniKyle , the FCTM said (see the highlighted):

So there's 2 condition where DECEL P/W (or the beginning of Approach Phase):

1. Automatic Activation, or

2. Manual Activation by Pilots.

This consist of 2 type of deceleration:

1. Passing SPEED LIMIT Altitude (250kt/FL100 and/or 220kt/FL060, incase of highspeed descend, identified by Magenta Dot) -> Passing DECEL P/W -> decelerating to GDot -> further decelerating to VApp at FAF/P, OR

2. Passing SPEED LIMIT Altitude (250kt/FL100 and/or 220kt/FL060, incase of highspeed descend, identified by Magenta Dot) -> Passing DECEL P/W -> decelerating to GDot -> Reduced to selected Speed Constraint (Either on IAF/P, IF/P, and/or FAF/P) -> further decelerating to VApp and to be established at VApp at FL010 AGL (IF there's a Speed Constraint on FAF/P).

Example 1: As you can see the picture below, the DECEL P/W becoming JUST BEFORE the runway:

As you can see the DECEL P/W just before the Runway because of there's speed constraint at point KARBO, while actual DECEL P/W SHOULD be between point EGURI to KKK892

Example 2:

Although there's no speed constraint, because of Glideslope capturing from High Altitude, the DECEL P/W become AFTER the FAF/P and start at Ground Level. (which should be before EWREQ point).

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I know there's a misunderstanding because on FCTM/FCOM mentioning DECEL P/W targeting VApp AT the runway, but actually combined with the FCTM above, it should be AT VApp just before passing 1,000 feet AGL to satisfy the Stabilized Approach Criteria for Instrument Approach.

And FYI, this structure is applied to ALL AIRBUS Aircraft, from A300-600 through A380. And therefore, it required ALL Airbuses by Inibuilds to be total makeover for DECEL P/W.

I hope this can be implemented on future update on every aircraft by IniBuilds. It's sad as an ex-A330F Driver to face this inaccurate modelling.

And I also hope this explanation will help. Cheers!

HaveASafeFlight!