Steering wheel lock (in aviation) - a device for parking fixation of the position of control surfaces (rudders) and parts of their control systems. It is used on the ground, when the aircraft is stationary, to exclude spontaneous rudder movements from the wind and prevent unnecessary kinematics wear ("loosening") or breakdowns. On aircraft with irreversible booster control, the stopper may not be installed, since in the absence of pressure in the hydraulic system, the control surfaces under their weight sink to the stop of the hydraulic booster rods and remain in this position. Due to the design features of the hydraulic drive, the rudders are little susceptible to spontaneous movement.
In helicopters, in order to prevent spontaneous rotation of the rotor during bad weather, a rotor brake is used - the mechanism is usually of friction type, and the rotor blades are moored to the fuselage with halyards (ropes).
Earlier in aviation, external mechanical stoppers - clamps were used to fix the rudders in the parking lot.
All the time the aircraft is on the ground, the control system must always be locked, except in cases of inspections and technical work directly related to the aircraft control system. Servicing the moving elements of the control system both inside and outside the aircraft is considered to be work with increased danger, requiring compliance with a number of certain rules - out of ignorance or carelessness, you can easily damage the aircraft or cause injury.
Description of the system (as an option)
At the same time, the locking system blocks the engine start levers in the Stop position, excluding the possibility of engine starting and the take-off of the aircraft with locked rudders. The rudder and ailerons lock in the neutral position, and the elevator is deflected to the lowest position, which eliminates the possibility of spontaneous locking in flight in case of failure of the locking mechanism or with careless use of the mechanism.
The elevator locking mechanism is located on the left (from the axis of the aircraft) propeller shaft mount bracket, that is, on the stabilizer, the rudder - on the bracket fixed at the bottom of the rear spar of the keel, the ailerons - on the bracket of the front center wing spar on the left. A locking device is installed in the left panel, which excludes starting the engines when the steering wheels are locked and the steering wheels are locked when (at least one) engine is running.
Links
- STEERING AND STEERING SYSTEM FOR STOPPING ENGINES (inaccessible link)