An aircraft control check is an essential safety check carried out by the pilots of an aircraft. A control check (also known as a flight control check) involves moving the control column of the aircraft in all possible directions to ensure proper functionality.
If flight control surfaces are visible from the cockpit, pilots can look to verify that they are responding correctly to the control inputs. A control check can also be performed on the aircraft’s rudder via inputs made on the rudder pedals.
Why perform an Aircraft Control Check?
The purpose behind performing an aircraft control check is solely for safety reasons. It’s better to realize the aircraft can’t be controlled on the ground than in the air!
Most aircraft control surfaces are linked to the control column via control cables. Over time, these cables can become worn and have the potential to break. Aircraft control cables could also have the potential of being incorrectly rigged or calibrated during maintenance. While correct aircraft maintenance should avoid this event ever happening, it’s always better to check before every flight.
What Flight Controls does a Control Check Cover?
When performing a flight control check, the control yoke of the aircraft is moved fully to the left and right to check that the aileron (roll) control surfaces are working correctly.
The same is repeated for the elevator (pitch) control surfaces, in which the pilot(s) move the control yoke forward and back to ensure free travel of the elevators.
A rudder control check is performed by applying full foot pressure to each rudder pedal respectively. Flight control checks may also include flap and speed brake/spoiler checks to verify that these devices are working correctly.
When performing these various checks, pilots are looking for visual, aural, and tactile cues to verify if the aircraft flight controls are working correctly. Visual cues are the control surfaces responding to corresponding inputs. Aural cues could consist of foreign noises being heard when inputs to control columns are made.
Tactile cues are mainly concerned with verifying free, fluid travel of the control surfaces. Pilots are trained to know the correct feedback from the controls. In the event of an inconsistency, they should be able to notice a change in how the controls respond to the inputs.
How Often Should an Aircraft Control Check be Performed?
An aircraft control check should be performed at least once prior to departure and also during post-maintenance inspections. This is to ensure that the flight controls and control cables are rigged to the correct calibration setting.
During the pilot’s visual inspection of the aircraft, control surfaces should be checked for signs of fatigue, rust, and potential obstructions. While this may not be possible on larger aircraft, smaller General Aviation (GA) are typically much more accessible in this regard.
Flight Control Monitor in the Cockpit:
Some modern commercial airliners by manufacturers such as Airbus and Boeing are often equipped with additional safety equipment. This safety equipment includes display pages on screens in the cockpit that show flight control movements. Known as the Flight Control System Display (F/CTL), it shows pilots an electronic indication of the flight control movements on input.
This is especially useful for aircraft in which it’s not possible to see flight control movements from the cockpit.
The F/CTL system enhances both safety and efficiency for pilots and engineers. This automated approach allows for easier diagnosis of potential flight control issues.
In conclusion, aircraft flight control checks should be a part of any checklist. This preventative approach allows for an issue to be identified before it becomes an in-flight safety hazard.