Autopilots

[superliner]

Hello,

The other day I was watching the AirForce One on TV and that set me thinking about the autopilots in the modern day airplanes. What I believed was that the primary function of the autopilot is to relieve the pilot of 'flying the airplane' once they had attained their cruising altitude. And maybe some other nice-to-have functions. What I found intriguing was that, in the movie, the President turns a knob somewhere on the flight panel to change heading to 230 or something...... without having to touch the flight controls, so what I'd like to know is if this is the autopilot flying the aircraft for you? Basically, I'd like to know if the autopilot can be used to fly the airplane for you.... without having to manipulate the flight controls and just key-in the required parameters. Is that right?

Superliner.

[Flexi]

Short answer:

Yes, thats right!

[Wizofoz]

On up to date aircraft, Autopilot can be engaged at 200' after take-off, and can stay engaged until AFTER landing (certain conditions regarding ground-based equipment being met).

[hetfield]

The Helios 737 was flown by the AP until the tanks became empty....

[Conan The Barber]

On up to date aircraft, Autopilot can be engaged at 200' after take-off

Always be careful generalizing. Some aircraft can have the AP engage from TO to landing. Other have a different limit than 200'. All examples are 'modern' aircraft.

[Graybeard]

Modern?

Beginning in 1973, the DC-10 equipped with the AINS-70 could be flown hands-off, takeoff to touchdown.

Air Force One was obsolete when built. They built a 747-300 when the 747-400 was already in service.

I read just one time that there was a comm problem on AF-1 on 9-11.

GB

[Northbeach]

The basic answer to your question is yes, when the autopilot is engaged the pilots interface with the jet using the flight management computer or various items on the autopilot control panel. With the autopilot engaged it is not necessary to manipulate the flight controls at all. In fact, by design with the autopilot engaged, manually moving the flight controls will in some cases disconnect the autopilot and trigger a number of warnings.

Currently produced autopilots are much more than devices just to relieve the pilot during cruise. Often learning the autopilot/automation of a new jet is the steepest single learning curve a pilot faces when checking out on a new type of airplane-and I don’t even fly an Airbus!

[superliner]

Guess my knowledge was obsolete through the stone age! So in case of airplanes where the autopilot is capable of take-off as well does it use the localizer of the ILS to maintain alignment with the RW?

[B737NG]

A/P

No, Take-off roll and rotation is done manually and when a stable climb is achived then the A/P can be engaged above 200 ft AGL in "modern" planes. Some modern Planes have higher limitation, 400 ft.

Fly safe and land happy

NG

[L337]

Some aircraft can have the AP engage from TO to landing

What aircraft?

[Flight Detent]

Hi Superliner...
just as a slight aside...
Just as an addition to what B737NG said, and, at least with the B737NG, those fitted with the (HUD) Head-up display(s), the runway localizer IS used for centerline guidance when doing a LVTO (low visibility takeoff), the HUD also provides a readout of the distance-to-run before the runway ends.

The height at which the autopilot can be engaged after liftoff is a regulatory issue, I believe, as the airplane will engage at any height.

But in the B737NG at least, the takeoff is controlled manually until airborne, as B737NG mentioned.

Cheers...FD...

[superliner]

So the take-off capability isn't necessarily in the repertoire of the autopilots. As for LVTO's are they also categorized as Cat I, Cat II.... paralleling the landing systems?

[Flexi]

No different categories for T/O! Below a RVR (runway visual range) of 400m, so called "low visibility operations" must be in progress and broadcasted by the airport.
Depending on the aircraft you operate, certain regulations have to be met which equipment must be available, who performs the takeoff-run and so on.

If you meet all the restrictions, you can legally takeoff!

The 737 classics, for example (without head-up guidance), are able to take off with a RVR as low a 125 meters.

Flexi

[Wizofoz]

Some aircraft can have the AP engage from TO

By that, do you mean in a CWS type mode as per the DC-10 and MD-11? Whilst I accept that technically the AP is engaged in that case, manual inputs are still needed.