Learn the causes of airplane landing gear failure, how crews diagnose unsafe gear, use backup extension and plan a safe emergency landing.
An airplane landing gear failure is usually caused by hydraulic or electrical faults, damaged locks or actuators, tyre or brake failure, structural damage, icing, maintenance error, or an abnormal touchdown. Pilots keep control, run the aircraft-specific checklist, use alternate extension, verify gear position, declare an emergency, and land in the safest available configuration.
In real-world aviation, “gear failure” covers several different events: the gear may not extend, may show an unsafe indication despite being locked, or may collapse after touchdown. Correctly identifying which problem exists matters more than trying random remedies.
What causes an airplane landing gear failure?
Most failures begin in the extension system, locking mechanism, position indication system, or the gear structure and wheels.
| Failure area | Typical causes | Likely result |
|---|---|---|
| Hydraulic system | Fluid leaks, failed pumps, damaged lines, stuck valves or leaking actuator seals | Slow, incomplete or asymmetric extension; brakes and nose-wheel steering may also be affected |
| Electrical and control system | Failed switches, wiring, relays, sensors or control units | No extension command, conflicting indications or a false gear-unsafe warning |
| Locks, doors and linkages | Jammed doors, damaged uplocks or downlocks, bent components or foreign objects | One or more legs remain retracted, trail partially extended or fail to lock |
| Wheels and brakes | Burst tyres, seized bearings, brake overheating or locked wheels | Loss of directional control or fire risk during the landing roll, even though the leg itself is down |
| Structure | Hard touchdown, excessive side load, fatigue, corrosion, overload or an unsuitable repair | Gear collapse, bending or separation |
| Environment or maintenance | Ice, mud, debris, incorrect rigging, poor servicing or an incorrectly fitted component | Restricted movement, unreliable locking or premature component failure |
Our guide to landing-gear locks, actuators and position indications explains how these components work together. Hydraulic faults deserve particular attention because the same pressure source may operate the gear, brakes and steering; see our explanation of aircraft hydraulic power and its backup systems.
A tyre burst or brake fire is often reported as a landing gear failure, although it may not affect extension or downlock integrity. Conversely, a perfectly intact gear leg can be unusable because its door, actuator or locking mechanism has jammed.
How do pilots handle a landing gear malfunction?
Pilots stabilise the aircraft first, then use the approved abnormal checklist to diagnose the fault and select the appropriate extension or landing procedure.
- Fly the aircraft. Maintain a safe altitude, speed and flight path. If the problem occurs during approach, a go-around normally creates the time and space needed for diagnosis.
- Identify the indication. Crews compare individual gear lights, warning messages, hydraulic indications and any mechanical position indicators. They also check whether the fault appeared after a specific action, such as selecting the gear down.
- Run the aircraft-specific checklist. Transport aircraft use the Quick Reference Handbook; light aircraft use the approved POH or AFM procedure. Repeatedly cycling the gear or resetting circuit breakers can worsen mechanical damage or restore power to a faulty circuit, so neither should be done unless the procedure directs it.
- Use alternate extension if required. Depending on the aircraft, this may release the uplocks for gravity extension, use a manual pump, or employ a separate hydraulic, electrical or pneumatic source. Alternate extension can leave the gear permanently down for the remainder of the flight.
- Confirm the actual configuration. Crews use every available independent indication. A tower visual check or another aircraft may identify an obviously retracted or misaligned leg, but an external view cannot prove that an internal downlock is secure.
- Plan the landing. ATC is advised, emergency services are requested, and the crew chooses a suitable runway. The cabin is briefed, loose items are secured, and shutdown or evacuation actions are reviewed before touchdown.
A long runway with a favourable wind, low crosswind component, suitable surface and rescue cover is normally preferred. The longest runway is not automatically best if it has a strong crosswind or poorer emergency support. Crews may hold to troubleshoot or reduce landing mass, but they do not burn or dump fuel automatically; sufficient reserve and any worsening hydraulic leak, fire risk or system damage must be considered.
Can a gear warning be a false indication?
Yes, a failed sensor, switch, wire or indicator can produce an unsafe warning even when the landing gear is mechanically down and locked.
Equally, an illuminated light does not excuse contradictory physical signs or system messages. Aircraft differ in their use of green, red and transit indications, so crews follow the type-specific logic rather than assuming that every “three green” system works identically.
A landing-gear warning horn is also not a complete diagnosis. It may be triggered by a combination of thrust, flap position, airspeed or radio altitude, depending on the aircraft. Pilots check the gear itself and the relevant warning-system conditions.
How is the landing flown with unsafe gear?
The approved checklist determines whether to land on the available gear, attempt another extension, or prepare for a gear-up landing; pilots should not retract working gear simply to make the configuration symmetrical.
| Configuration | General handling aim | Main concern |
|---|---|---|
| All gear appears down, but one indication is unsafe | Use the prescribed landing configuration, minimise side load and make a smooth touchdown | The affected leg may collapse despite appearing extended |
| Nose gear unsafe or retracted | Touch down on the main gear and keep the nose clear for as long as controllable, following the type checklist | Loss of steering, forward fuselage damage, sparks and fire |
| One main gear unsafe | Use the aircraft-specific asymmetric-gear technique and expect control authority to reduce with speed | Strong yaw, wing drop and possible engine or wing contact |
| All gear retracted | Prepare for a controlled belly landing at the attitude and speed specified for the type | Structural damage, fuel leakage, propeller or engine contact and fire |
| Gear collapses during rollout | Maintain directional control, stop, shut down as directed and assess whether evacuation is needed | Rapid yaw, blocked exits, hot brakes and leaking fuel |
Nose-gear cases have their own control and braking considerations, covered in our detailed safe landing procedure after a nose-gear failure. Exact speeds, flap settings, braking limits and engine shutdown actions vary by aircraft; generic figures should never replace its checklist.
Should pilots go around after a gear warning?
A go-around is normally the safer choice when a late warning leaves insufficient time to complete the checklist and establish a stable approach, provided the aircraft has enough fuel and no worsening condition makes another circuit more hazardous.
Reasons to land without delay can include fire, severe fuel leakage, rapidly declining hydraulic pressure, flight-control effects or critically low fuel. If another approach is made, the crew accounts for the drag of partially extended gear and uses the abnormal-configuration speed specified by the manufacturer.
What happens after a landing gear failure?
After the aircraft stops, the crew secures engines and systems, coordinates with rescue services and evacuates only when fire, smoke, fuel leakage or another immediate hazard makes remaining aboard less safe.
Maintenance personnel then support or jack the aircraft before moving it, inspect locks and structural attachment points, and examine hydraulic, electrical and indication systems. A hard-landing inspection may be required even when the gear remained standing. The warning light alone does not establish the cause; recorded data, component examination and the crew’s observations are used to distinguish an indication fault from genuine mechanical or structural failure.