Can a Computer Fly an Airplane?

Here are some of the main ideas students should take away from this video:

• The computer system on the A330 aircraft controls the plane’s speed, altitude, and flight path and monitors all the aircraft’s systems.
• Pilots on the A330 do not pull large handles and levers to turn the plane or change its altitude; they have a small joystick that relays commands to the computer system, which carries out those instructions.
• The computer system actually executes pilot commands; if a pilot command is unsafe, the computer will not carry it out.
• If the pilot sends a command to the computer to turn the plane, the computer will make the turn and compensate for the drop in altitude by increasing power and lifting the nose of the plane to move it back up.
• Pilots can set a course and then fly hands-free while the computer carries out the commands.
• If the pilot is disabled or loses control of the joystick, the computer system on the plane will take over to keep the plane from crashing.

• At what point does the computer system carry out a pilot command?
• Why might “automation improve safety”?

NARRATOR: Powerful computer systems are designed to control everything from air speed and altitude to turning the aircraft. The design philosophy: that automation improves safety.

In a flight simulator, veteran pilot Martin Alder demonstrates the features of these computer systems.

MARTIN ALDER (Airbus Training Pilot): Gear up.

In a conventional airplane, instead of this side-stick, I'd have quite a big control column here. You need plenty of leverage to apply the mechanical forces you need to move the control surfaces to control the airplane.

NARRATOR: In a conventional airplane, the pilot pulls mechanical levers to operate a hydraulic control system. But on the A330, this heavyweight gear is replaced by an electronic system called "fly-by-wire."

The pilot tells the flight computer what he wants to do, but it is the computer that translates this intention into action and executes the maneuver.

MARTIN ALDER: So if I want to go to the left, stick to the left, round to the left.

NARRATOR: The flight computer adjusts the control surfaces, and the aircraft turns. Maneuvers like this cause the A330 to lose altitude, so the advanced computer compensates by increasing power and pitching the nose up to provide the right amount of lift. The pilot does nothing.

MARTIN ALDER: I take my hands off, and there we are, it's flying round. Vertical speed, 0; 25 degrees of bank; 240 knots; it's going to fly around at 25 degrees of bank, and keep doing this until we get bored.

NARRATOR: The flight computer won't carry out any pilot command that endangers the safety of the aircraft.

MARTIN ALDER: If the pilot were to lose control for some reason, the system would save the airplane.