reply to post by ULTIMA1
ULTIMA.....your ignorance of the B757 and B767 is becoming more and more evident, with your claim of their autopilots being able to be
pre-programmed!!!!! The autoflight system will dis-connect when sufficient force is applied to the control column. There is a dis-connect button on
each control wheel. There is a dis-connect button on the MCP.
The auto-pilots can be re-connected by use of one of the three buttons on the MCP. If a 'higher' mode is not selected yet on the Flight Director,
the Auto-pilot will engage in to basic pitch and roll modes...altitude hold and heading hold. (three buttons....Left, Center, and Right)....yes,
three autopilots, since the airplanes are certified for 'fail-active' AutoLand capability....which would have saved UAL93 if the Pax had been able
to get the bastards out of the cockpit before they killed everyone!!
NOW, as to the auto-pilots being pre-programmed.....you are not fully understanding the system.
At the gate, we 'initialize' the IRS. Nowadays, we have the benefit of GPS updating, much much more accurate!!
We look at what the FMC tells us, on the screen....the GPS position. We check it against the Jeppeson 10-9 chart, the Airport Diagram, with Lat/Longs
for all the gates. If it jives, we press a button, bringing the Lat/Longs to the scratchpad, then 'line select' to the 'Position' boxes....and
the alignment begins.
Somewhere along the line, when we continue to initialize, with flight number, then there's a Flight Plan uplink.....this goes into the Flight
Management Computer....it is in the database, usually every city pair has a number of 'canned' Flight Plans, the Dispatcher selects which Route to
use, based on weather conditions, and wind conditions. We already know which Route to expect, since we get a printed copy of the Flight Plan in
Operations, and we sign the Dispatch Release. When it uplinks, then we check it against the printed copy. Hey, if it's different, usually we will
also get an uplink message from Dispatch, explaining why, and the Gate Agent will get a new Flight Plan send to their printer, and they hand it to us
with the Final Paperwork....along with the final Weight & Balance info.....
The FMC has the Flight Plan stored....except for the Departure Runway, the Departure Procedure (the SID) and the STAR and arrival runway at
destination....we put those in, not only to sync up the entire Route, but to have the data there for Navigation purposes, and to get a full mileage
number, which we then compare to the printed Flight Plan...AGAIN...to make sure it jives.
Of course, departure runways can change, arrivals can change, we do that during the taxi, or inflight, depending.
FINAL point!!! The AutoPilot CANNOT take over the airplane!!! You are seriously mis-informed if you believe that to be true.
I have already told you thre are three ways to dis-connect the autopilot....it can also be easily over-powered with normal human strength.
AND....there are circuit breakers that can be pulled....heck, you could de-power the main buses if needed!!!!! Airplane flies just fine on Standby
Power!!!!
SO....no Auto-Pilot takeover, NO WAY, NO HOW!!
WW
spelling booboos, as usual...
[edit on 4/26/0808 by weedwhacker]
