AFS Abnormal Operations

The reset deep-dive was article 29; this article is the treatment table for the ECAM AUTO FLT warning family: AUTOLAND (red), AP OFF (red), A/THR LIMITED, A/THR OFF, FCU FAULT (partial/total), FM 1(2) FAULT, FM 1+2 FAULT, FMGEC VERSIONS DISAGREE, REAC W/S DET FAULT, TCAS MODE FAULT — plus two cross-chapter relatives (the electrical-emergency table and the flight-controls family's FMS PRED UNRELIABLE line). The generic reading for every entry: trigger + action line(s) + STATUS (which capability grade remains) + INOP SYS (which equipment-table rows are gone — cross-read with article 12).

1. Two reds and a nag

AP OFF. Per FCOM PRO-ABN-AUTO_FLT:

L2 This alert triggers when this warning is displayed only for involuntary disconnection. For voluntary disconnection a red AP OFF message is displayed in the right lower part of ECAM upper DU.

The continuous warning is reserved for the involuntary case (article 05's two warning shapes); a takeover-button disconnect earns only the self-clearing red memo. The procedure is one line — crew awareness: fly the aircraft first, then ask why it was taken (article 05's three hands).

AUTOLAND. Per the same chapter:

Note: If the autopilot is disengaged below 200 ft AGL using the instinctive disconnect pb, the AUTOLAND lights will flash for 3 s. If visual references are insufficient, initiate a go-around. GO-AROUND......PERFORM

The procedural face of article 13's night watchman — including the benign case: a manual AP disconnect below 200 ft also flashes the light 3 s (you triggered the "no AP in the last segment" condition yourself). The programme's single action line: visual references insufficient → go around.

A/THR LIMITED. Per the same chapter:

L2 The caution is repeated every 5 s as long as the thrust levers are not moved. L1 If all engine operative: THR LEVER...CLB In case of engine out: THR LEVERS (REMAINING ENGINES)...MCT

The five-second nag (article 17) with exactly two answers: CLB two-engine, MCT engine-out — return the levers to article 16's standard authorisation positions.

2. A/THR OFF — the other-AP recovery and the freeze

Per FCOM PRO-ABN-AUTO_FLT:

L2 If A/THR is failed, the flight crew may recover it by engaging the other AP, and then trying to re-engage the A/THR. Note: If the A/THR is recovered with AP 2, A/THR will be lost again at AP 2 disengagement. L1 THR LEVERS...MOVE L2 Thrust is frozen after autothrust disconnection until the thrust levers are moved.

The recovery method leans on article 16's mastership rule: an A/THR dead on the master's side may revive under the other AP's mastership. And the printed trap: an A/THR recovered with AP2 dies again the moment AP2 disengages — mastership defaults back to side 1 (article 29's frozen-speed trap, benign edition; the landing answer is the same — selected speed and A/THR off before AP2). The single action line: move the levers — the thrust-lock release (article 17); left unmoved, ENG THRUST LOCKED repeats every 5 s. STATUS: CAT 2 ONLY — article 12's A/THR column (0/1/1), cashed.

3. FCU FAULT — half a body, then none

Partial failure (one channel left): actions are cross-checking the baro reference (FCU against PFD) and re-selecting AFS targets as needed; STATUS files PART FCU — which is where article 02's "no in-flight reset on PART FCU" connects. Total failure, the full ledger article 02 previewed:

PFD BARO REF: STD ONLY L2 With all FCU channels failed, the barometer reference goes to 1 013 hPa. Use standby altimeter to change this to the actual barometer setting. Do not insert the MDA (MDH) value on the MCDU PERF APPR page (because the PFD altitude is referenced to STD, not to the correct barometric value). The PM shall then perform the standard callouts ('HUNDRED ABOVE' and 'MINIMUM'), using the STBY altimeter.

The PFD locks to standard; true altitude lives on the standby altimeter; do not insert the MDA — entered against an STD-referenced PFD it would generate callouts at a false altitude, so the PM makes the hundred-above and minimum calls by hand off the standby instrument. Also lost: all FCU controls, A/THR + both APs + both FDs (except in LAND/GA, where only the A/THR goes — article 02's exception), altitude alerting, the TRK-FPA and MACH selections; the ND freezes at ARC 20 NM (weather-radar display possibly flagged), bearing pointer 1 = VOR 1, pointer 2 = ADF 2.

4. The FM failure family — one key, three steps, two brackets

FM 1(2) FAULT (one side): the action is one line — FM source selector to BOTH ON the healthy side (both NDs on one source — article 19's SINGLE). STATUS: CAT 3 SINGLE ONLY; INOP: AP 1(2), FM 1(2), CAT 3 DUAL.

FM 1+2 FAULT (both): three steps, verbatim:

FM SOURCE...NORM L2 The FM source selector must be at NORM, to allow the NAV B/UP prompt to be displayed on the MCDU MENU page L1 NAVAID TUNING...USE RMP L2 Set both RMPs to NAV L1 LDG ELEV...ADJUST L2 CPCs normally use the Landing Elevation from the FM.

NORM (the backup-navigation prompt's precondition — article 19), both RMPs to NAV (article 20's back door), and the one non-obvious step: set the landing elevation by hand — the cabin pressure controllers normally take the field elevation from the FM, and with both FMs dead the cabin no longer knows where to descend to (article 29's CAB PR LDG ELEV FAULT, as procedure). The STATUS page's bracketed items are diagnostics: AP 1 + 2 (1) … REAC W/S DET (2) … (1) (If the FG parts of the FMGES are lost) (2) (If the FE part of the FMGES is lost) — whether the APs and the windshear sentry survive depends on whether the FM died alone or took the whole FMGEC with it (article 19's contrast pair, written into the STATUS brackets). And the note: DH indication lost → ILS limited to CAT 1.

FMGEC VERSIONS DISAGREE. Per the chapter: this alert triggers when the aircraft is equipped with two different FMGEC standards — two software standards aboard (a component change without the ground crossload — article 04's gates, evaded). The action is only crew awareness, but the INOP list bites: AP 1(2)(1+2) plus A/THR — with the versions at war, the guidance group walks out. The no-dispatch line of article 01, experienced airborne.

5. Two sentries hand in their badges

REAC W/S DET FAULT: the reactive windshear sentry off duty (article 18) — crew awareness; operationally, shear protection is down to the predictive system (ATA-34) and your eyes. TCAS MODE FAULT:

FOR TCAS ALERT AP+FD.....OFF FLY MANUALLY TCAS ORDER

The AP/FD TCAS mode is broken — this ECAM is the switch between article 15's two playbooks: from now on, an RA means AP and FDs off, hand-fly the green sector.

6. Two cross-chapter blocks

The electrical emergency configuration (PRO-ABN-ELEC tables): in the EMER columns the FCU shows "1 only" — half an FCU, one FMGEC (article 01's power tiers as procedure). The AFS in electrical emergency is a minimum build: re-assess the approach against the remaining capability with article 12's table.

FMS PRED UNRELIABLE (a STATUS line in the flight-controls family):

(4) Disregard FMS fuel predictions and Refer to QRH/OPS Fuel Penalty Factors/ECAM Alert Table in order to find the applicable Fuel Penalty Factor.

When spoiler/SEC failures change the aerodynamics, the STATUS page stamps the FMS's fuel arithmetic unreliable outright — ignore the EFOB, open the fuel-penalty table (article 25's credit boundary, given an ECAM doorway; the same STATUS also carries FUEL CONSUMPT INCRSD and a capability downgrade).

7. The QRH 23 family — and the generic three steps

The QRH's navigation/auto-flight procedures, indexed to their deep-dive articles: Abnormal V Alpha Prot (monitor; margin under 15 kt — no higher, no faster — article 18); IR alignment in ATT mode (steady 30 s, SET HDG, cross-check the standby compass — article 20); NAV FM/GPS POS DISAGREE (the scenario tree — article 20); the FMGEC reset ladder (article 29); and unreliable airspeed — whose AFS-side action is simply all three off (AP, A/THR, FD) before the pitch/thrust memory values.

The generic treatment frame (synthesis, valid across the family): ① fly the ECAM action lines (usually one or two); ② take STATUS/INOP to article 12's equipment table — the real question is which approach grade remains; ③ follow the link back to the mechanism article for the monitoring focus (after A/THR OFF, watch THR LK; after a single FM death, watch for INDEPENDENT symptoms).

[!warning]- Four misconceptions this article corrects (1) The AUTOLAND light flashing after your own low disconnect is not a malfunction — you triggered the "last AP gone below 200 ft" condition; the light's one question is still "go around?". (2) An A/THR recovered under AP2 is borrowed, not repaired — it dies again at AP2 disengagement; before landing, selected speed and A/THR off first. (3) In total FCU failure, entering the MDA would arm callouts against a false (STD) altitude — the PM calls hundred-above and minimum from the standby altimeter instead. (4) The STATUS brackets after FM 1+2 FAULT are a diagnosis, not decoration — AP and windshear-detection survival depends on whether FG and FE died with the FM.

Self-test

[!note]- Q1. The ECAM difference between voluntary and involuntary AP disconnection?

Involuntary: the continuous AUTO FLT AP OFF warning. Voluntary (takeover button): only the self-clearing red AP OFF memo in the ECAM's corner.

[!note]- Q2. What happens if you disconnect the AP manually below 200 ft on an autoland — and the AUTOLAND procedure's action?

The AUTOLAND lights flash for 3 s — expected, you created the condition. The procedure's single action: if visual references are insufficient, go around.

[!note]- Q3. A/THR LIMITED's two answers — and where do LIMITED and OFF leave the capability?

Levers to CLB (all engines) or MCT (engine-out). LIMITED is a lever-position nag (capability intact once resolved); A/THR OFF stamps STATUS with CAT 2 ONLY.

[!note]- Q4. The other-AP recovery's mechanism — and its "lost again" trap?

Engaging the other AP moves the A/THR mastership to the healthy FMGEC, allowing re-engagement. Recovered under AP2, it is lost again at AP2 disengagement (mastership defaults to side 1) — hence selected speed and A/THR off before disconnecting AP2 to land.

[!note]- Q5. Total FCU failure: the altitude reference, the MDA rule, and who makes the minimums calls?

The PFD locks to STD (1013); the actual setting goes on the standby altimeter. Do not insert MDA/MDH (the PFD altitude is false for that purpose); the PM makes HUNDRED ABOVE and MINIMUM manually from the standby instrument.

[!note]- Q6. FM 1+2 FAULT's three steps — and why is landing elevation manual?

FM source to NORM (enables the NAV B/UP prompt); both RMPs to NAV for tuning; landing elevation adjusted by hand — the cabin pressure controllers normally take it from the FM, which is now dead.

[!note]- Q7. What does the "(1)" after AP 1+2 in the STATUS mean?

That the APs are lost only if the FG parts of the FMGES are lost — FM-only death leaves them; whole-FMGEC death takes them. The brackets diagnose which layer died.

[!note]- Q8. FMGEC VERSIONS DISAGREE — the scenario and the INOP list?

Two different FMGEC software standards aboard (a swap without the ground crossload). INOP: the APs and the A/THR — the guidance group refuses to arbitrate between two standards.

[!note]- Q9. After TCAS MODE FAULT, how is an RA flown?

The no-mode playbook: AP and FDs off, hand-fly the TCAS order (the VSI green sector) — this ECAM is the switch between the two procedures.

[!note]- Q10. Where does FMS PRED UNRELIABLE appear, and the correct response?

As a STATUS line in aerodynamics-changing failures (spoilers/SEC family): disregard the FMS fuel predictions and find the applicable fuel-penalty factor in the QRH — the ECAM doorway to the manual-fuel-arithmetic rule.

Key takeaways

References

The AUTO FLT warning family — triggers, actions, STATUS and INOP entries — per FCOM PRO-ABN-AUTO_FLT (AP OFF, AUTOLAND, A/THR LIMITED/OFF, FCU FAULT partial/total, FM 1(2)/1+2 FAULT with its bracketed diagnostics, FMGEC VERSIONS DISAGREE, REAC W/S DET FAULT, TCAS MODE FAULT). Electrical-emergency AFS remainder per FCOM PRO-ABN-ELEC; FMS PRED UNRELIABLE and the fuel-penalty pointer per FCOM PRO-ABN-F_CTL. QRH navigation-family procedures per a representative operator QRH, deep-dived in the linked articles. The generic three-step frame is an integrative synthesis.

Independent study material, not an Airbus publication and not endorsed by the manufacturer. Always defer to the current operator FCOM, FCTM, and QRH for operational use.