Reverser Faults — REV UNLOCKED, AUTO RESTOW Consequence, Reverse Unavailable
Thrust Reverser gave normal operation + the AUTO RESTOW logic; Engine Displays the REV indication. This article takes the fault side: REV UNLOCKED, the consequence after AUTO RESTOW (idle for the rest of the flight), reverse unavailable at landing, and the hydraulic coupling.
1. Reverser-fault display
REV in amber: The thrust reverser system is unlocked. In flight, the REV indication pulses during 9 s and then remains steady.
Per DSC-70-90-40: REV green = fully deployed on ground (normal reverse); REV amber = unlocked (fault/unlocked), in flight pulsing 9 s then steady.
2. The AUTO RESTOW consequence
The FADEC will automatically command the engine to idle and the reverser to stow if at least one door is unstowed by more than 5 % and reverse thrust is not selected while engine is running. The affected reverser will remain pressurized after affected door is locked back. If the door is still detected unstowed, the engine will remain at idle for the remainder of the flight.
Per DSC-70-70: a door unstowed > 5 % with reverse not selected while running → FADEC commands idle + stow; the reverser stays pressurised after the door locks back; if it still reads unstowed, the engine stays at idle for the rest of the flight.
[!warning]- Worst case: that engine locked at idle for the rest of the flight (no high thrust) A door unstow > 5 % triggers AUTO RESTOW (idle + stow); if it still reads unstowed → that engine stays at idle for the remainder of the flight (DSC-70-70) — meaning that engine can only idle thereafter, flying on effectively single-engine usable thrust. The serious consequence of an inadvertent unlock.
3. Reverse unavailable + hydraulic coupling
- Landing needs reverse but REV unlocked/fault → that side's reverse is unavailable; deceleration relies on brakes + spoilers + the other side's reverse (landing-distance impact).
- Hydraulic coupling: reverse is actuated by blue (engine 1) / yellow (engine 2) hydraulics (09) → a failure of that hydraulic system → that engine's reverse unavailable (ATA 29 cross-chapter).
The full REV UNLOCKED ECAM handling is in PRO-ABN-ENG (this article carries 09's AUTO RESTOW automatic logic + display; the exact ECAM steps stay in the manual).
4. Counterintuitive points
| Symptom | Meaning | Consequence |
|---|---|---|
| REV amber | reverser unlocked | unlocked/fault |
| door unstow > 5 % (reverse not selected) | AUTO RESTOW | idle + stow; if still unstowed → idle for rest of flight |
| landing REV unavailable | no reverse that side | brakes / spoilers / other side's reverse |
| blue/yellow loss | no reverse power | reverse unavailable (ATA 29) |
[!warning]- A 5 % door unlock can "lock the engine at idle for the whole flight" A door unstow > 5 % that persists → idle for the rest of the flight (unrecoverable, 09). One door's unlock can leave an engine able to idle only thereafter.
[!warning]- A reverser fault may come from hydraulics (not the engine) Reverse runs on aircraft hydraulics (blue 1 / yellow 2) → a hydraulic-system failure also makes reverse unavailable (09). When reading a reverser problem, think hydraulics (ATA 29).
Self-test
[!note]- Q1. What does REV amber mean? The reverser system is unlocked; in flight it pulses 9 s then steady.
[!note]- Q2. The worst case after a door unstow triggers AUTO RESTOW? A door unstow > 5 % that persists → that engine stays at idle for the rest of the flight (no high thrust).
[!note]- Q3. How to decelerate at landing with REV unavailable? Brakes + spoilers + the other side's reverse (landing distance affected).
[!note]- Q4. Which system failure couples into reverse? Hydraulics (blue 1 / yellow 2) — that hydraulic loss → that engine's reverse unavailable.
Key takeaways
| Point | Detail |
|---|---|
| REV amber | unlocked; AUTO RESTOW: unstow > 5 % → idle + stow, persists → idle rest of flight |
| Landing | reverse unavailable → brakes / spoilers / other side |
| Coupling | reverse depends on hydraulics (blue 1 / yellow 2) → hydraulic loss couples in |
| Handling | full REV UNLOCKED in PRO-ABN-ENG |
References
- FCOM DSC-70-70 (09) — AUTO RESTOW (door unstow > 5 % → idle + stow, persists → idle rest of flight) / blue-yellow hydraulics.
- FCOM DSC-70-90-40 (14) — REV amber = unlocked (in flight pulses 9 s).
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.