reply to post by 767doctor
All excellent points, and summarized well.
A little more, from the "pilot's" perspective as well, regarding the complexities of any "remote takeover", and its applications, to include a
full Auto Landing sequence. I'll try to 'walk' you through it....
This concept would
be considered as a possible 'practical' solution to the nearly inconceivable circumstance of BOTH (or sometimes,
ALL THREE - rarely FOUR) pilots becoming incapacitated, and as a last-ditch method to save the airplane and occupants.
(However...the odds of such a need are so astronomical...the cost and complexity of a system, not only installation by CONTINUED maintenance of it?
Costly beyond any real
In order to effecuate a FULL descent, arrival to the terminal area of an airport, and all the way to include final approach on the ILS....yes, it CAN
be programmed into the FMS and FMC. ALSO, the AutoPilot and AutoThrottles have to be engaged.
Here is an image showing a typical MCP (A Boeing 777, in this case):
Variables exist, i.e.
, the 777 has TWO A/T switches, etc. BUT, the differences are minor, between airplane types.
However, in reality, it isn't normally pre-programmed in its entirety...in day-to-day operations, it is far more complicated, to the ever-changing
demands of the complex ATC environment.
BUT, let's say the capability to remotely program the FMC was in place, to insert all of the waypoints, the landing runway at the selected airport,
etc, into the computer memory, and execute the program. AND, engage an autopilot in proper modes (LNAV and VNAV).
THEN, other buttons have to be selected, to change the functions...the ILS has to be 'armed' (so that the system will 'capture', and track the
signals). The ILS receivers -- BOTH -- of them have to be tuned to the proper frequency. (ILS won't even 'arm' unless they are tuned, first).
All along, speed will be changing (decelerating) and slats/flaps will have to be selected to extend, on schedule with the airspeeds. Eventually
(about 5-7 miles from touchdown) the landing gear will have to somehow be triggered to extend (this is, like slats/flaps, normally accomplished by
physically moving levers).
The airspeeds can be pre-programmed into the FMS, at selected points within the programmed route. We actualy use that sometimes, for reference in the
VNAV mode. BUT, again...we program manually, as needed. AND, often change them, as needs arise.
Anyway...in order to select the 'AutoLand' mode, the airplane has to be down to within the Radar Altimeter's indication range, which is below 2,500
AGL. Then the procedure is to press the AutoLand button on the MCP, and all THREE A/Ps engage. The A/L only engages in that mode when other
criteria are met, as well.
Finally, the speed brakes have to be armed to the 'AUTO' ground spoiler position (another handle to physically move, to a detent) AND the AutoBrake
selector switch is rotated to an autobrake setting...usually '3' for A/L. (We use the mnemonic...CAT III approach, brakes '3', CAT II, brakes
'2'...or '3', if the runway is wet, etc....)
An autoland is NOT a 'simple' procedure. So much would have to be designed, and tested, and then installed and maintained...in addition to the
REGULAR scheduled checks of the normal A/L components, to remain 'CAT III' authorized....
It is so cost-prohibitive, as to be impractical in reality.
[edit on 11 June 2010 by weedwhacker]