Applications of Springs in Aircraft Engineering

If an examination were made of virtually every Subject Topic of every Section of every Chapter of the many Aircraft Maintenance Manuals, complying with the ATA Specification No. 100 (from Air Conditioning through to Accessory Gearboxes), then numberless examples would be found of the applications involving the use of springs in aircraft engineering. Many applications have already been mentioned but some further examples of the uses for springs are:

• Pressure Regulating/Limiting Devices in Fuel, Hydraulic, Lubrication, and Pneumatic systems.
• ‘Fail Safe’ or ‘Return to Neutral Condition’ Devices in Electrical Relays and Solenoids and also in Electric, Hydraulic, Mechanical, or Pneumatic Actuators.
• Acceleration and Speed Control Devices in Engine and Propeller control systems and in Power-Assisted Flight Controls and Wheel Braking systems.
• Shock Absorbing Devices in Landing Gear systems and as Anti-Vibration Mountings for delicate instruments and components which are subject to movement.
• Devices that are capable of applying a constant force (linear or rotary) in a desired direction, as in the holding closed of an aero-engine valve spring for one example.
• Devices with the ability to accurately indicate the value of an applied force, as used in many instruments (Ammeters, Voltmeters, Fuel Flow Meters and Tachometers provide typical examples).

Note: The subject of spring technology is vast and well beyond the scope of these notes, so it is sufficient for the student to appreciate the basic uses for springs in the aerospace environment and the functions that they fulfil.