6.2 Retraction, Steering, Anti-Skid, and Warning Systems

Gear Retraction and Steering: Verify the Sequence

Retractable landing gear systems move heavy parts through a controlled sequence. They may use hydraulic power, electric motors, mechanical linkages, uplocks, downlocks, doors, switches, warning horns, and cockpit indications. The Airframe ACS emphasizes troubleshooting a landing gear retraction check because a missed step can create aircraft damage or a false sense of safety.

A retraction check is not started by simply selecting gear up. The aircraft must be supported according to the manual, the area must be clear, gear pins and locks must be managed as directed, hydraulic and electrical power must be controlled, and personnel must stay out of the movement path. Operation of retractable gear around people is specifically a risk-management concern.

Good troubleshooting follows the sequence. If the gear will not retract, the fault may be power supply, pump output, motor operation, selector valve, squat switch logic, door linkage, uplock rigging, actuator leakage, mechanical binding, or a safety interlock. If the gear will not extend or lock, the cause may be hydraulic pressure, free-fall system condition, downlock adjustment, door interference, actuator issue, or structural misalignment.

Use this sequence map while studying:

• Confirm aircraft support, power source, and safety precautions.
• Verify cockpit selector, circuit protection, switches, and warning logic.
• Observe gear doors, uplocks, actuators, downlocks, and mechanical linkage.
• Check indications against actual gear position, not assumption.
• Inspect hydraulic or electrical power components after controlling pressure and power.
• Adjust switches, locks, and rigging only by the aircraft procedure.
• Perform functional checks and document discrepancies and corrective action.

Gear warning systems reduce the chance of a gear-up landing. A warning horn or light may be triggered by throttle position, flap position, gear handle position, squat switch status, or other aircraft-specific logic. A nuisance warning may still indicate a faulty switch or rigging error. A missing warning can be more dangerous because the pilot may not be alerted.

Nose-wheel steering problems also need system thinking. Shimmy can come from tire imbalance, worn torque links, low strut pressure, loose bearings, worn steering linkage, shimmy damper issues, or alignment. A technician should not replace the shimmy damper without inspecting the rest of the system. Steering that feels stiff may involve linkage binding, cable or rod adjustment, hydraulic steering faults, or mechanical interference.

Anti-skid systems monitor wheel behavior and reduce brake pressure to prevent skids. Maintenance may include checking sensors, control units, wiring, valves, warning systems, and operational tests. Because some tests require aircraft-specific equipment or procedures, the safest answer uses the manual and avoids improvised live checks.

For the written exam, the best choices usually confirm actual gear position, follow a logical fault path, and respect stored energy and moving parts. Indication errors, warning faults, and shimmy reports are never solved by assumption.