What functions can the autopilot control perform on a modern aircraft?

An autopilot can be very much nowadays.The autopilot is connected to the Flight Management System (FMS) in aircrafts, under this system the Flight Management Computer (FMC), Automatic Flight Control System (AFCS), the navigation system and the Electronic Flight Instrument are System (EFIS).

In the FMC a whole flight plan can be programmed, also several other data, such as wind speed during cruise, noise abatement procedures and holdings, can be introduced.On the basis of the FMC, the FMS can control the aircraft, the pilot only need to turn on the vertical navigation (V NAV) and lateral navigation (L NAV) buttons of the autopilot. The plane then follows the entire programmed route and also automatically stops climbing at the cruising altitude.

The following functions are then performed by the autopilot:

  • Autothrottle (A/T): the cruise control.
  • Heading (HDG): The direction the device flies on.
  • Altitude (ALT HLD): Hold the altitude of the plane.
  • Vertical Speed (V/S): speed with which the plane is lifted.
  • Follow SIDs (Standard Instrument Departure Routes): A standard route that fly a plane after the take-off to the first airway (say the highway for planes) on the route.
  • Follow STARs (Standard Terminal Arrival Routes): A standard route from the airway to the place where the approach phase starts.
  • Track the programmed route.
  • Gas to prevent noise pollution.
  • Trimming the plane.
  • Watch patterns Fly (holding)

In addition, Autopilots can now also fully automatically land, which is generally only done in dense fog.This is done via the Instrument Landing System (ILS) which is divided into different categories (based on sight and to what extent there can be landed without input from the pilot):

  • CAT I: At a decision height (where the pilot should decide to make a go-around) of 61 meters is the sight 550 meters or more.

Autopilot is not necessary.

  • CAT II: At a decision height between 30 and 61 meters, the visibility is at least 300 meters.
  • The autopilot must be a fail-passive, or if the autopilot fails, the pilot must still be able to control the plane.

  • CAT IIIa: At a decision height of 15 meters, the visibility is at least 200 meters.
  • The autopilot must be a fail-passive.

  • CAT IIIb: Practically the same as IIIa, but on the runway the plane also has to roll automatically.
  • And at a decision height below 15 meters, the visibility must be at least 76 meters. The autopilot must be fail-operational, or the landing must still be done automatically.

  • CAT IIIc: Practically the same as IIIb, but no decision height is required.
  • Unfortunately not yet available in traffic planes.

    In the image above[1 you can see which functions of the autopilot are enabled or which are automatically enabled.


    [1 Image on b737.org.uk

    It’s very much there.

    With Google you can look up how much it is there, but a few general functions I can give:

    • Auto-Throttle 脗 -‘ A kind of cruise-control for airplanes, ensures that the plane must fly at the same speed.
    • HDG (heading) ensures that the plane continues to fly in the same direction (same number of degrees).
    • ALT (altitude) ensures that the aircraft continues to fly at the same altitude or climbs to that altitude.
    • US (Vertical Speed) ensures that the plane goes up at a steady speed.
    • Navigation System 芒 -‘ ensures that the plane flies its route.

    (This is settled at the beginning of the flight.)

    I hope I have given a good enough answer to the question.If anyone finds an error in my answer, please let me know!

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