"carl mciver" wrote in message
nk.net...
"Rex B" wrote in message
...
|
| Jon Elson wrote:
| Not likely. The average airliner has so little in common with
the
| average lightplane that the pilot would just change the scene of the
| crash. Airliner navigation systems are so complex that he wouldn't be
| able to figure out where he was, much less get the thing configured
and
| lined up for a workable approach and landing, and things like gear
and
| flaps slats and spoilers and reverse thrust can keep two experienced
| pilots plenty busy. Just figuring out how to disable the autopilot
| might take time.
|
| It's my understanding that the newest airliners can land themselves
| without pilot input. Is that true?

Yes and no. The system, ALS (I think,) automated landing system,
requires special equipment on the ground. IIRC, Boeing has two of their
fields certified by the FAA, Paine Field and Moses Lake in Washington
state
(Moses Lake is a big flight test spot for them) but it ain't cheap and so
very few other airports have used it. It also requires special software
be
installed in system capable airplanes (meaning digital controls, not old
stuff) that combine the inputs from many of the aircraft's system and fed
into the autopilot. You have to have all your mechanical controls be
operable by computer, which means it has to be fly by wire. No control
cables or anything. Airbus' philosophy about flying is to let the
computer
make the decisions with "requests" from the pilot (hence some interesting
accidents early on in the program) and Boeing's philosophy is to let the
pilot be in control of the plane at all times, although the computers do
help out a lot by assuming control of most systems when so directed. You
can override the systems on any Boeing airplane just by moving the
controls
where you need them to go, unlike their competitor's planes which require
you to remember where the "please let me have the plane back" button is.


The only true fly by wire surfaces on the 767 are the spoilers/speedbrakes.
All other flt. control surfaces are conventionally operated by cables,
bellcranks, etc. On a cat IIIa or b approach, the autopilots will
disconnect with pilot input up to a certain point on the approach. After
that, any force inputs to the control wheel will not cause a disconnect. He
can't override the autopilot manually. He would have to disconnect at the
a/p disconnect switch on the control wheel or knock down the engage handles.
It's definitely a different philosophy than Airbus. And the right one, in
my opinion. If better airplanes are built, Boeing will build them.
And cat IIIa is not really a zero altitude and zero RVR landing.
(Runway visual reference, how far can you see looking through the fog down
the runway.) If the pilot is on a cat IIIa approach, he must have at least
700' RVR, (measured by instruments adjacent to the runway and called out to
him by the tower), and must be able to see the runway at 50' radio altitude
or he's got to go around and try again. Or divert to another airport. Cat
IIIb is true 0 alt. and 0 rvr and provides nosewheel steering from the
localizer radio beam down the runway. Cat IIIc is rollout guidance. The
airplane will steer itself to the gate area. The airport has to be
certified for all this and have small transmitters buried in the tarmac for
guidance. I know Heathrow used to be setup for this. The only aircraft I
ever worked on that was Cat IIIc certified was the Lockheed L-1011. They
very rarely used it, however. That system was a bitch to maintain, but
Lockheed sure built a good, solid airplane.

Garrett Fulton