# Aircraft Nose-Wheel and Main-Wheel Steering Systems

> Ground steering principles, tiller and rudder-pedal authority, and body steering logic to reduce tyre scrubbing and landing gear loads.

- **Subject:** 021 — Airframe, Systems, Electrics, Powerplant
- **Section:** 021-04 — Landing Gear, Wheels, Tyres, Brakes
- **Topic code:** 021-04-02
- **Last reviewed:** 2026-03-27
- **Author:** Pablo Asensio Martínez
- **HTML version:** https://pilotsyllabus.com/en/airframe-systems-electrics-powerplant/landing-gear-wheels-tyres-brakes/nose-wheel-steering/

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Steering on the ground is primarily achieved through the nose wheel, but larger aircraft may also employ main-wheel steering. The system is typically hydraulically powered and controlled via a tiller or rudder pedals.

## Main-Wheel (Body) Steering

Large aircraft with multiple main gear wheels mounted on bogie beams can experience high sideways loads and tyre scrubbing during tight turns.

- **Purpose:** to reduce **stress on the torsional links and reduce tyre abrasion** (scrubbing).
- **Operation:**
    - It is **only used in slow speed tight turns**.
    - The main wheels steer in the opposite direction to the nose wheel.
    - It turns sideways forces into longitudinal forces on the main gear assemblies.
    - **Benefit:** Reduces the turning circle radius.

## Nose-Wheel Steering Control

Nose wheel steering is hydraulically powered and activated only when the aircraft is on the ground (controlled by squat switches).

- **Control Methods:**
    - **Hand Wheel Steering (Tiller):** Used for low-speed, high-angle turns (e.g., parking). It provides **large deflection** (typically up to 78 degrees).
    - **Rudder Pedals:** Used for high-speed steering (e.g., takeoff and landing roll) and minor corrections during taxi. It provides **limited deflection** (typically up to a maximum of 7 degrees).

- **Operational Considerations:**
    - **Deflection Comparison:** Manual/tiller steering offers a significantly **larger maximum deflection** of the nose wheel compared to rudder pedal steering.
    - **Rudder Check:** When performing a rudder control check during taxi, an **additional pilot action must be taken** (disconnecting the steering) to avoid unwanted deflection of the nose wheel, which would cause the aircraft to swerve.
    - **In-Flight:** Rudder pedal nose-wheel steering **does not function in the air**.

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Free study notes from pilotsyllabus.com. Not a substitute for training at an approved ATO.