Many aircraft have systems within them that are actuated by a cable and pulley system. These systems can control flight controls, engine operations, and auxiliary support systems. Some of these systems are critical to flight. In most cases, the failure of any of these cables will result in a need to terminate the flight at the safest and most expedient opportunity.
Many aircraft have flight control systems that are actuated by cable and pulley systems. These systems commonly include the rudder (which controls side to side motion), the elevator or stabilator (which controls up and down motion) and the ailerons (which control roll motion). These systems are connected to the cockpit control input systems (the yoke or control stick and the rudder pedals) through a system of cables and pulleys.
The pilot controls the flight direction of the aircraft through the movement of the control systems, which moves the cables to move the flight control surfaces on the aircraft. Breakage of any of these cables may result in the failure to be able to control the direction of the aircraft.
Controls for power settings, mixture settings, and alternate air sources for the aircraft's engine may also be controlled by a cable system. Failure of a cable for the power setting would mean that the pilot cannot change power settings.
If this failure occurs at a low power setting, the pilot may not be able to maintain altitude. Failure at a high power setting may require the pilot to turn the engine off to descend and complete the final landing.
Failure of mixture controller cables will result in failure to manage the engine. Alternate air systems cable failures will critically affect aircraft instrument readings. With failure of any of these systems, it is generally advisable that the pilot terminate the flight.
Aircraft have other systems that also may operate using a cable system, such as carburetor heat systems, defrosting systems, and rudder pedal adjustments. In each of these cases, failure of a cable will not result in the immediate need to terminate a flight.
Aircraft that have cable systems integrated into their mechanical systems should be regularly inspected to verify the integrity of the systems. Cables should be regularly inspected for fraying, cracking, or general wear and tear. These inspections should be conducted by, or with the help of an FAA certified maintenance professional.
It is more common for smaller, general aviation aircraft to have systems of this type. Most larger, commercial aircraft have hydraulic or new modern electronic flight control systems.
