Above the Clouds: Keeping Planes in the Air

Controlling an aeroplane is not an easy feat, yet many highly trained pilots do it several times a day, cashing in hours and hours of flight.

So, how exactly does a pilot control such a massive flying machine? Let’s find out!

First off, let’s start with some aeroplane anatomy basics… A regular aircraft has three basic rotational movements: pitch, yaw, and roll. Each of these elements is controlled by a different control surface – ailerons on the wings control roll, the rudder on the vertical tail controls yaw, and the elevator on the tail horizontal stabiliser controls pitch.

These are little known even to the most frequent flyer. You might be more familiar with things like the engine control, the flaps, the slats, and speed brakes. However, the most important piece of the puzzle is the control trim.

But what is the control trim? The control trim is an avionic system that frees the pilot from having to exert constant pressure over the controls. It’s often used to keep straight and level flight, though it can be used at any phase of the flight – for example, to maintain a constant rate of climb or descent.

Most modern jets have auto-trim features. As the name suggests, the system adjusts automatically depending on the selected power setting and attitude. When the auto-trim is enabled in modern aircrafts, the wheel moves on its own as the pilot makes changes to any of the main control surfaces.

The auto-trim benefits are undeniable, since it allows the pilot to focus on other tasks while flying the plane and to perform controlled and efficient manoeuvres. These tasks can vary from communicating more effectively with traffic control teams to focusing more on air traffic and other aspects of the journey.

The auto-trim is only one of many ways that avionics can benefit from automation. Three other well-known automated elements of aircraft are the autopilot, the auto-throttle and the flight management system, all of which are just as important as the auto-trim.

On a lighter note and perhaps coming as quite the surprise, pilots of regular aircraft typically spend only ten minutes manually controlling the aeroplane. These short ten minutes happen during take-off and landing, and the rest of the journey is fully automated while the pilots use that time to verify other important functions, like traffic control.

From control surfaces and flaps, to much more complex systems like the control trim and autopilot, aircraft are fantastic flying machines whose safety must be ensured. Automation plays a very important role in aviation these days, with most aircraft being almost fully automated, which in turn poses some safety challenges. Safety-critical verification and validation activities have never been so important, and they must take place to avoid jeopardising aviation safety. Have a look at what we offer in the field of aviation and aerospace.

Want to dig even deeper? Read our aerodynamics 101 article and check out our white paper for more information about what happens inside aeroplanes and the ‘magic’ that keeps them in the air.