Autoland and Rollout

Article 12's qualification cashes out here as action: the LAND → FLARE → ROLL OUT relay manages the aircraft from 400 ft to the end of the landing roll. This article covers the three modes, the AUTOLAND red light that stands watch over the last 200 ft, the certification envelope, and the monitoring flow.

 400 ft RA            ~60 ft RA          touchdown           runway exit / go-around
   |────── LAND ─────────|────── FLARE ──────|────── ROLL OUT ──────|
   tracks LOC + G/S       decrab + break the    derotates the nose +
                          descent rate          steers the centre line
                          (A/THR → IDLE)

On the FMA all three are common modes — they occupy columns 2 and 3 merged (the FCOM files them under "AP/FD Common Modes - Column 2 and 3", with LAND's display condition simply the Land mode is engaged below 400 ft RA). Article 06's taxonomy becomes visible here: in the last 400 ft there is no separate "vertical mode" and "lateral mode" — only one landing task. And a special message keeps the exit lit: FOR GA: SET TOGA — per FCOM DSC-22_30-80-20, the flight crew must set the thrust levers to the TOGA detent to perform a go-around (article 14).

1. LAND — 340 feet with no undo key

Per FCOM DSC-22_30-40-80:

The LAND mode is a common vertical and lateral mode. The LAND mode tracks the LOC and G/S beams from 400 ft RA to approximately 60 ft RA.

LAND automatically engages, when all the following conditions are applicable: ‐ The approach and landing capability is CAT1, CAT2 or CAT3, and ‐ LOC and G/S are engaged, and ‐ The aircraft is below 400 ft RA.

No button engages LAND — it engages itself. And no button disengages it:

LAND automatically disengages, when the aircraft approximately reaches 60 ft RA: FLARE engages. When LAND is engaged, no action on the FCU can disengage LAND. The flight crew can only disengage LAND by performing a go-around.

FCU immunity: once LAND is up, winding the altitude knob, pressing APPR, pulling HDG — nothing works. The design refuses to let a slipped hand interrupt an automatic landing inside 400 ft; the only sanctioned change of mind is TOGA. The QRH's "at 350 ft check LAND green" is the confirmation that this lock has latched — 350 ft is the check point, 400 ft is the engagement line, the 50 ft gap being the system's time to declare itself. One ground-side detail from the AMM: after touchdown the LAND-chain latch releases only after 10 seconds on the ground with the AP disconnected — which is why the FMA still shows the landing family during the roll until the AP comes off.

2. FLARE — one mode, two hands, and the thrust comes off by itself

Per FCOM DSC-22_30-40-80:

The FLARE mode is a common lateral and vertical mode: ‐ Lateral guidance: The FLARE mode reduces the sideslip angle, such that the aircraft will be aligned with the runway centerline at the aircraft touchdown ‐ Vertical guidance: The FLARE mode decreases the descent rate, in order to ensure a comfortable transition between the glide tracking, and the aircraft touchdown. ‐ If the A/THR is active, the thrust is automatically reduced to IDLE.

FLARE engages, if all the following conditions are applicable: ‐ The aircraft approximately reaches 60 ft RA ‐ The approach that the flight crew selects is either an ILS approach, a GLS approach, or an RNAV(GNSS) approach with LPV minima (with SLS ). L2 FLARE engages only if the following conditions are applicable: ‐ The slats/flaps are extended, or the landing gears are extended ‐ One valid RA.

FLARE automatically disengages, when the aircraft touches down: ROLL OUT engages. The flight crew can only disengage FLARE by performing a go-around.

Decrab to the centre line, break the sink rate, and — with A/THR active — bring the thrust to idle. The RETARD callout then has two different meanings at two different heights. Per FCTM AS-FG:

During flare, with the A/THR active, the thrust levers are set to the CLB detent. Then, when thrust reduction is required for landing, the thrust levers should be moved rapidly and set to the IDLE stop. This will retard thrust, and set A/THR to off. As a reminder, the 'RETARD' aural alert will sound. In flare, this aural alert will occur at 20 ft, except in the case of autoland, where it occurs at 10 ft.

Manual landing: RETARD at 20 ft is a command — reduce the thrust now. Autoland: RETARD at 10 ft is an administrative nudge — FLARE already pulled the thrust to idle; the call asks you to bring the levers to the idle stop so the A/THR disconnects cleanly at idle (article 17). The QRH autoland card writes both beats into the flow: at 30 ft check the THR IDLE mode, at 10 ft RETARD and levers to idle.

3. ROLL OUT — derotate and steer

Per FCOM DSC-22_30-40-80:

The ROLL OUT mode is a common lateral and vertical mode: ‐ Lateral guidance: the ROLL OUT mode guides the aircraft along the runway centerline ‐ Vertical guidance: The ROLL OUT mode lands the nose landing gear.

The "vertical guidance" of a mode that is already on the ground: flying the nose gear down. Exits:

ROLL OUT disengages, when one of the following occurs: ‐ The aircraft exits the runway, or L2 Note: When the difference between the aircraft track and the runway track is more than 20°, the ROLL OUT disengages due to the APs and FDs disengagement. ‐L1 The flight crew engages a go-around.

During the roll the AP steers through the BSCU's nose-wheel steering and the rudder (article 12's equipment-table footnote — BSCU/anti-skid/steering are required only if automatic rollout is intended). Autobrake is disconnected before 20 kt (QRH card).

4. The AUTOLAND red light — night watchman of the last 200 ft

Article 12 ended with the capability display latched below 200 ft; this light takes over the watch. Per FCOM DSC-22_30-80-10:

The AUTOLAND red lights flash when: ‐ At least one AP is engaged below 200 ft RA, with LOC and G/S armed, or with LOC, G/S, LAND or FLARE engaged, and the radio altimeter indications differ by more than 15 ft, or ‐ At least one AP is engaged below 200 ft RA, with LAND or FLARE mode engaged, and one of the following conditions occurs: • The last AP disengages, or • The aircraft excessively deviates from the ILS beams (See 1), or • The ILS signal is lost (See 2), or • A long flare (1 000 m with FLARE engaged) is detected, or • A too-early flare (FLARE engages less than 2 s after LAND engagement) is detected.

Note: 1. LOC deviation 1/4 dot above 15 ft RA, GLIDE deviation 1 dot above 100 ft RA (LOC or GLIDE scale flashes on the PFD) 2. LOC signal is lost above 15 ft RA, or GLIDE signal is lost above 100 ft RA (FD bars flash on the PFD, and LAND mode remains engaged).

Read footnote 2 twice: losing the ILS signal does not eject LAND — the system continues on its memorised references while the red light hands the decision to you (in low-visibility operations, red light = go around, per company procedure). The excess-deviation flash thresholds (¼ dot LOC, 1 dot GLIDE) are the landing-zone red lines, tighter than the en-route monitors. And note the height floors in both footnotes: below 15 ft (LOC) / 100 ft (GLIDE) even the red light stays silent for these causes — the go-around window has passed, and the system chooses not to distract.

5. The autoland envelope

Per FCOM LIM-AFS (autoland section, airframe group modelled here):

ILS CAT II and CAT III autoland and GLS CAT I autoland are approved in CONF 3 and CONF FULL. Automatic landing is demonstrated: - With CAT II and CAT III ILS beam and CAT I GLS beam. - With a glide slope angle between -2.5 ° and -3.25 ° - For airfield elevation below 9 200 ft - For weights above 116 000 kg (255 737 lb) - With aircraft weight below the maximum landing weight

Note: Depending on the situation (e.g. emergency or other) and provided that the runway is approved for automatic landing, the flight crew can decide to perform an autoland up to 229 t (504 858 lb).

Automatic rollout performance is approved on dry and wet runways, but performance on contaminated runways was not demonstrated.

The emergency note is worth filing: an overweight return without fuel dumping can still elect an autoland up to 229 t on an approved runway. Contaminated runways: the landing may be automatic but the rollout was never demonstrated — plan an early manual takeover of directional control. One configuration caution: a different airframe group's LIM page adds a forward-CG limit line that the group modelled here does not carry — envelope questions are answered on your airframe group's page, never a neighbour's (article 04's configuration-page rule again).

Autoland on a CAT I station (or an unprotected CAT II/III one) — good weather practice included — has four prerequisites:

‐ The airline has checked that the ILS beam quality, and the effect of the terrain profile before the runway, have no adverse effect on AP guidance. In particular, the effect of terrain discontinuities within 300 m (974 ft) before the runway threshold must be evaluated. ‐ The flight crew is aware that LOC or G/S beam fluctuations, independent of the aircraft system, may occur. The PF is prepared to immediately disconnect the AP and to take the appropriate action, should unsatisfactory guidance occur. ‐ At least CAT 2 capability is displayed on the FMA, and CAT II/III procedures are used. ‐ Visual references are obtained, at a DH appropriate for the CAT I approach being flown, or a go-around is performed.

The reason for the armour: a CAT I station's sensitive areas are not protected — taxiing aircraft stir the beam. Hence the full set: airline-verified beam and terrain, a PF primed to disconnect, CAT II/III procedures with at least CAT2 displayed, and honest CAT I visual minima.

6. Flying it — the monitoring flow

The QRH autoland card (following the LOC G/S card's final segment):

•At 350 ft RA ILS/GLS /MLS COURSE ON PFD................... CHECK Monitor auto callout •At 40 ft RA FLARE mode......................... CHECK ENGAGED / ANNOUNCE •At 30 ft RA THRUST IDLE mode ........................................................CHECK •At 10 ft RA : autocallout 'RETARD' ALL THRUST LEVERS ......................................................... IDLE LATERAL GUIDANCE..................................................MONITOR •At TOUCH DOWN ROLL OUT mode...................CHECK ENGAGED / ANNOUNCE

Then: "SEVENTY KNOTS" with reversers to idle, autobrake off before 20 kt, reversers stowed at taxi speed. Notice the same check-lag philosophy as 350/400: FLARE is checked at 40 ft though the mode engages at ~60 ft — callout points trail mechanism points, giving the system its window to declare.

Engine-out autoland: article 12 gave the LIM side (CONF 3, procedures complete by 1000 ft); the FCTM adds the A/THR's credentials. Per FCTM AS-FG:

Use of A/THR is recommended during the entire flight. It may be used in most failures cases, including: ‐ Engine failure, even during autoland ‐ Abnormal configurations.

And the ground-verification layer (awareness): after AFS component replacement — or periodically for CAT III operators — maintenance runs the LAND CAT III test: FIDS-hosted, it verifies the system's ability to execute a CAT3 DUAL fail-operational automatic landing, together with the takeover buttons, the A/THR instinctive disconnects and the autoland warning; it starts only after all four computation lanes (FG1/FG2, command and monitor) post their LAND TEST acceptance, and only on the ground with engines stopped (article 01's FIDS gate). The pilot-level meaning: CAT III capability is not only computed on the FMA — it is demonstrated on the ground.

[!warning]- Five misconceptions this article corrects (1) Below 400 ft there is no FCU exit from LAND — knobs and buttons are dead to it; the only change of mind is TOGA. (2) The RETARD call means different things: at 20 ft (manual) it commands the thrust reduction; at 10 ft (autoland) the thrust is already at idle — it asks for the levers, so the A/THR disconnects cleanly. (3) Losing the ILS below 200 ft does not eject LAND — the system continues on memorised references and the red AUTOLAND light hands you the decision. (4) The autoland envelope is not "any runway, any weight": CONF 3/FULL, glide −2.5° to −3.25°, elevation < 9200 ft, weight above 116 t — with a deliberate emergency allowance to 229 t. (5) A practice autoland on a CAT I station is not casual — unprotected sensitive areas mean beam fluctuation; it takes the airline's beam check, CAT II/III procedures, CAT2 capability and a disconnect-ready PF.

Self-test

[!note]- Q1. LAND's three engagement conditions — and why does the QRH check at 350 ft when the clause says 400?

Capability CAT1/2/3 displayed, LOC and G/S engaged, below 400 ft RA. 400 ft is the engagement line; 350 ft is the check point — 50 ft of grace for the system to declare itself.

[!note]- Q2. LAND is engaged and you want to break off with HDG — can the FCU do it? What is the correct exit?

No FCU action can disengage LAND. The only exit is a go-around — thrust levers to TOGA (the FMA has been telling you so: FOR GA: SET TOGA).

[!note]- Q3. FLARE's lateral task? What does the A/THR do in FLARE, and at what heights does RETARD sound for manual versus automatic landings?

Reduce the sideslip so the aircraft is runway-aligned at touchdown (decrab). With A/THR active, thrust reduces automatically to IDLE. RETARD: 20 ft manual, 10 ft autoland.

[!note]- Q4. What does ROLL OUT's "vertical guidance" control — and what is the mechanism of its exit when the track diverges more than 20°?

It lands the nose gear (derotation). Beyond 20° track-versus-runway difference, the APs and FDs disengage — and ROLL OUT falls with them; that is the "aircraft exits the runway" detection.

[!note]- Q5. The five AUTOLAND-light triggers — the excess-deviation numbers and height floors — and does LAND drop when the ILS signal is lost?

Below 200 ft with AP engaged: RA split > 15 ft; last AP disengages; excess beam deviation (LOC ¼ dot above 15 ft, GLIDE 1 dot above 100 ft — scales flash); ILS signal lost (above the same floors — bars flash); long flare (1000 m in FLARE); too-early flare (FLARE within 2 s of LAND). And no — LAND remains engaged on signal loss; the light gives you the decision.

[!note]- Q6. The envelope's dimensions — and when may 229 t be used?

CONF 3/FULL; certified beams; glide −2.5° to −3.25°; elevation below 9200 ft; weight above 116 t and below MLW. Up to 229 t by crew decision in an emergency-type situation, provided the runway is approved for automatic landing.

[!note]- Q7. Is automatic rollout approved on a contaminated runway?

No — dry and wet only; contaminated performance was not demonstrated. Plan early manual directional control.

[!note]- Q8. The four prerequisites for an autoland on a CAT I station?

Airline-verified beam quality and pre-runway terrain (including discontinuities within 300 m of the threshold); crew awareness of possible beam fluctuation with the PF ready to disconnect immediately; at least CAT2 on the FMA with CAT II/III procedures; visual references at an appropriate CAT I DH or go-around.

[!note]- Q9. May the A/THR stay in for a single-engine autoland?

Yes — the FCTM recommends A/THR for the entire flight and keeps it usable in most failure cases, explicitly including engine failure during autoland.

Key takeaways

References

LAND, FLARE and ROLL OUT clauses per FCOM DSC-22_30-40-80; AUTOLAND warning triggers and footnotes per FCOM DSC-22_30-80-10; FMA common-mode entries and FOR GA: SET TOGA per FCOM DSC-22_30-80-20. Autoland envelope, 229 t note, rollout runway states and CAT I-station prerequisites per FCOM LIM-AFS (airframe-group specific — verify your own group's page). Monitoring card per a representative operator QRH. RETARD mechanics and engine-out A/THR credentials per FCTM AS-FG. Ground latch release and the LAND CAT III test per AMM 22-13-00 and 22-97-00. GLS/SLS/MLS wording is quoted as printed; those functions are not installed on the baseline airframe of this series.

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.