Driving a helicopter chassis cleaning
Driving a helicopter chassis cleaning

Driving a helicopter chassis cleaning


Retractable landing gear and flaps should be automatically locked in an extended and retracted positions. Nodes fixing should prevent accidental release of the chassis while normalized operating overloads, folding it in the parking lot, during taxiing and towing the helicopter forward and backward. The system provides a locking device, excluding its cleaning when crimped racks.

Wheels and rack when issuing and taking away does not have to pass through the space reserved for the external suspension.

And retraction of the landing gear is carried by one arm (crane switch, buttons). Lever (territory) cleaning and landing gear must have fixed positions ("remove" and "released") and locking of these provisions.

The cockpit provides alarm retracted and extended position landing gear installed PA locks.


On helicopters used hydraulic system cleaning and landing gear, which has the following advantages:

  • high power hydraulic actuators;

  • the possibility of applying high pressures, can benefit from the power cylinder and posting small size;

  • smaller mass compared with the electrical system;

  • greater reliability of operation in comparison with the electrical and pneumatic systems.


The simpler CCS chassis, the system reliability for its extension and retraction. In addition to the main landing gear control system must be established emergency or backup system.

Emergency landing gear extension system can be hydraulic, mechanical, pneumatic shgi using special squibs,

In the extended and retracted the landing gear locks are fixed. Landing gear doors closed.

Driving a helicopter chassis cleaning

Load on the piston rod of the power cylinder from the forces of gravity and the aerodynamic forces are determined in accordance with the kinematics and retraction chassis for several locations. Manufacturing and the landing gear is usually set tactical and technical requirements.

retracting nose Scheme (tail) landing gear is relatively simple. Nasal (tail) racks are cleaned in the fuselage "up- front" or "back up-". Driving clean "upper forward" ensures the release of the rack under the action of gravity and dynamic pressure even in case of failure of onboard energy sources. In some cases, in the same way may be issued and the main landing gear.

The schemes for the release and retraction of the main landing gear are significantly more diverse. On 6.10.2, the KKS is shown for cleaning the main landing gear of an experimental Boeing-360 helicopter.

retraction scheme 1

Recommend any particular constructive design of the landing gear is very difficult. In essence, each creates its own helicopter and constructive power circuit chassis. Even the size of the rack not only depend on the take-off weight of the helicopter, but also on the scheme and purpose. For example, the transport helicopter should have a very low chassis to ensure that the requirements for operation on the ground.

Wheels cleaning process can be pivoted relative to the column so that the landing gear in the retracted position occupied smallest volume. To combat helicopter a very important requirement is the simplicity of the kinematic scheme of the landing gear. Manufacturing and fixing of racks should be less than the fall of the helicopter with an estimated altitude during the emergency landing.


Features hydraulic mechanisms cleaning and landing gear


Dependency P = f (b) is called a diagram of the mechanism and retraction, where P - the need to provide a force or cleaning of the landing gear; 5 - stroke mechanism.

Pressures on the rod of the power cylinder from the forces of gravity and aerodynamic forces are determined in accordance with the kinematics and retraction for four to seven provisions of the chassis.

During extension and retraction chassis amortstoyka rotated continuously relative to the air flow. Loads pa rod cylinder power depend on the applied forces, points of their application and the kinematic scheme of the chassis. Each movable chassis construction joints and seals in the power cylinder when the frictional forces arise that provide additional load on the rod of the power cylinder. These loads are generally defined roughly as some fraction of the inertial and air forces.


Driving chassis with two mechanisms of extension and retraction


Installation of the second mechanism is suitable:

  • - when, with a low coefficient of completeness of the diagram of the operation of the lift when retracting the chassis, the required force can be

It achieved only by expanding the working area of ​​the lift, which will increase the overall energy system;

  • - when it is generally impossible to retrace the chassis with the help of one retraction and release mechanism. 

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