Engine Failure & Single-Engine Ops

This syllabus splits "single engine" into three layers of time: the instant of failure (ENG FAIL — decide whether to rescue, and whether rescue is possible), after the confirmed shutdown (ENG SHUT DOWN — inventory what that side no longer provides), and how to fly what remains (the manufacturer's handling technique, and the single-engine circling procedure). A promise made in article 00 is honoured here: an engine failure costs far more than thrust — the SHUT DOWN inoperative list is the casualty roll of the six gearbox accessories mapped in article 02.

1. ENG 1(2) FAIL — three forks at the instant of failure

"This alert triggers when engine core speed is below idle with MASTER sw ON, and FIRE pb not pushed."

The trigger definition is itself the diagnosis (synthesis): MASTER still ON means you didn't shut it down — the engine dropped off the line by itself (flameout, damage, or a broken shaft). The procedure's skeleton is a three-way fork:

Fork one: SHAFT FAILURE

"In the case of SHAFT FAILURE (for RR engines): The FADEC automatically shuts down the engine."

The thing you could never react to in time, the FADEC has already done — the closing of two protective layers: the LP turbine overspeed logic of article 05 (comparing the two shaft-end probes, cutting fuel through the shutoff valve) and the mechanical fail-safe shaft of article 01 physically restraining the fan. Your part is the aftermath, on the takeoff leg: gear up → lever idle → MASTER OFF → FIRE pushbutton PUSH + AGENT 1 + both inner-tank SPLIT pushbuttons ON — a broken shaft is handled as damage: power cut, fuel cut, agent fired, and the inner tanks compartmented against a possible leak.

Fork two: the 30-second window

"ENG START SEL IGN — Selection of continuous ignition confirms the FADEC's immediate relight attempt. It also protects the remaining engine. … IF NO ENG RELIGHT AFTER 30 S: The 30 s countdown starts as soon as the ENG 1(2) FAIL alert is triggered. ENG MASTER (AFFECTED ENGINE) OFF."

During these 30 seconds the FADEC's auto-relight (article 05) is already fighting for the engine — your selection of IGN is a second, not a motion: it confirms an attempt already in progress. And the same switch movement buys flameout insurance for the healthy engine (article 11) — the instinctive defence against a common-cause threat to both. Window expires with no relight → MASTER OFF, and on to fork three.

Fork three: the damage judgment

IF DAMAGE: FIRE pushbutton + AGENT 1 after 10 seconds (the same ventilation-decay logic as article 17) + SPLIT ON — with the proviso "If no fuel leak is evident, set both INR TK SPLIT pb-sw back to the normal position". IF NO DAMAGE: ENG RELIGHT CONSIDER → article 26.

Two closing notes deserve their own memory slots: once the FIRE pushbutton is pressed, the FADEC loses power — that engine's data goes silent for good; and in extreme low-speed cases (GPWS, windshear), at light weight VMCA/VMCL may be reached before α max — under full asymmetric thrust, control runs out before protection does. Sustained high vibration → reduce speed and altitude hunting for the practical minimum-vibration regime; plan landing in CONF 3 (preselect on the MCDU).

2. ENG 1(2) SHUT DOWN — the resource ledger of the one-engine world

The procedure's spine: LAND ASAP / ENG START SEL IGN (protecting the live engine) / L/G UP (takeoff display) / FUEL IMBALANCE MONITOR (suppressed in the engine-feed-pipe-rupture case) **/ TCAS MODE SEL TA / SECONDARY FAILURES: ELEC HYD.

Four mechanism notes ride the procedure text: the yellow electric hydraulic pump runs automatically if engine 2 fails before flap retraction (switch it off manually once clean); the windmilling engine briefly trips a hydraulic low-pressure warning → switch off that side's pumps (only when no restart is intended); TCAS to TA — single-engine climb performance cannot honour an RA's demands; and the asymmetric-thrust control note already filed in §1. The STATUS branch for a ruptured engine feed pipe dovetails with the fuel chapter: outer-tank transfer ON + straight flight + autopilot off + 3° of bank toward the live engine + full same-side rudder to hold heading + rudder trim — gravity transfer needs a roll head of pressure; restore items one by one once the transfer completes. In that case the usual fuel-imbalance line stays hidden deliberately: the imbalance is the evidence, not something to trim away.

The INOP list, audited against article 02's six accessories (engine 2 shutdown shown):

The slats/flaps asymmetry is the memorable one (synthesis): shut down number 1 and the slats slow; shut down number 2 and the flaps slow — a direct consequence of which hydraulic system drives which high-lift channel.

3. Handling technique: the beta target, and the price of TOGA

"In the case of an engine failure at takeoff, the blue beta target appears instead of the usual sideslip indication on the PFD. The lateral normal law will react to a detected thrust asymmetry and command some rudder surface deflection to minimize the sideslip (there is no feedback of this command to the pedals). Therefore, laterally, the aircraft is a stable platform and no rush is required to use the rudder pedals. However, since the lateral normal law does not order the entire rudder surface deflection, the flight crew must adjust the rudder pedals as usual to center the beta target in order to optimize the climb performance."

Three sentences, one complete loop: the aircraft steadies itself first (the law commands partial rudder, with no feedback to the pedals — no rush); you top it up at leisure (pedal until the blue beta target centres — the law never gives full deflection, and climb performance lives in that remainder); and if full rudder still won't centre it, accelerate — more speed, more rudder authority, less rudder needed. Then rudder trim takes the load off your leg, and only with the trim settled does the autopilot come in — after engagement the trim belongs to the autopilot and feet come off the pedals: sustained pedal force can disconnect it. Pitch on the takeoff leg: 12.5° initial target, SRS holding the speed at failure (V2 to V2+15).

The TOGA price list: from a FLEX takeoff, pushing TOGA is legitimate and buys margin — at the cost of simultaneously increased yawing moment and pitch rate, a heavier handling load. From a derated takeoff, TOGA below the F speed carries a WARNING — the controllability logic met in articles 00/08: a derate is a controllability commitment, not a convenience.

4. The single-engine circling weight gate

The QRH circling procedure carries a table: maximum weight for circling in CONF 3 with gear down, double-entry by OAT and airport elevation — from 232 (×1000 kg) at sea level, 0–25 °C, shading down to 146 at 14 000 ft / 25 °C. And the instruction for the heavy case:

"If aircraft weight above maximum weight: DELAY GEAR EXTENSION TO MAINTAIN LEVEL FLIGHT."

The table's essence (synthesis): in the CONF 3 + gear-down drag configuration, this is the weight ceiling at which one engine can hold level flight in the circle. Above it, the answer is not "don't circle" — it is extend the gear later, keeping the biggest drag item for last. The cost is two low-altitude callouts to anticipate and manage: circling below 750 ft RA triggers L/G GEAR NOT DOWN (the EMER CANC pushbutton is the procedure's sanctioned mute), and 500 ft RA without gear brings the GPWS "TOO LOW GEAR".

Self-test

[!note]- Q1. The three elements of the ENG FAIL trigger? When does the 30-second countdown start? Core speed below idle + MASTER ON + FIRE pushbutton not pressed (= nobody shut it down on purpose). The countdown starts at alert triggering — not when you select IGN.

[!note]- Q2. Why does the shaft-failure handling feel backwards? Because the FADEC has already shut the engine down (the LP turbine overspeed protection) — your actions are aftermath (FIRE pushbutton / agent / tank split), not rescue. The mechanical fail-safe shaft is restraining the fan throughout.

[!note]- Q3. Shut down engine 1 — which high-lift surface slows, and which hydraulics are lost? SLATS SLOW (engine 2 would slow the flaps); lost are BLUE hydraulics (engine 2: YELLOW), that side's green-system EDP, and alternate braking.

[!note]- Q4. Full rudder and the beta target still won't centre — next move? Accelerate — rudder authority grows with speed and the required deflection shrinks. Then trim the load off, and hand over to the autopilot with feet off the pedals.

[!note]- Q5. Circling weight exceeds the table — what do you do? Delay gear extension to maintain level flight, and pre-brief the two low-altitude warnings (GEAR NOT DOWN at 750 ft RA — mutable with EMER CANC — and TOO LOW GEAR at 500 ft).

Key takeaways

References

• FCOM PRO (engine abnormal procedures: ENG 1(2) FAIL complete section — trigger, shaft-failure auto-shutdown, 30 s window, damage branches, GPWS/VMCA note, CONF 3; ENG 1(2) SHUT DOWN complete section — procedure spine, mechanism notes, feed-pipe-rupture STATUS branch, full INOP list) — quoted verbatim.
• FCTM (engine failure after V1) — 12.5°/SRS, the beta-target loop, the acceleration clause, trim-to-autopilot handover, TOGA considerations and the derate WARNING.
• QRH (one engine inoperative — circling approach) — the weight table, the delay-gear instruction, the two low-altitude callouts.
• Integrative synthesis (marked in text): the trigger-as-diagnosis reading; seconding-not-moving; the slats/flaps asymmetry explanation; the table's level-flight essence and the delay-gear logic.

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.