reply to post by Insolubrious
757s and 767s can be flown entirely under the control of their flight management computer systems (FMCS), according to Boeing.
Ah, but those same computers and systems will NOT allow the airplane to exceed certain limitations and parameters.
The autopilot will NOT allow the airplane to exceed 30° angle of bank, for example. UAL 175's angle appeared to be more than that, as the pilot
was correcting his aim, by increasing the abnk angle to the left in the last seconds.
The speeds would NOT exceed Vmo when controlled by the AutoFlight systems.
Merely because the FDRs and that information is not available for AAL 11 and UAL 175, it is not logical to presume that "they" were different from AAL
77 and UAL 93, for which we DO have the data and proof of human intervention, on the controls. WITH the autopilots disconnected.
One more thing.....UAL 175.......the transponder
. Which is perfect, since this thread began with that subject in the first place.
Unlike the other three hijackings, the transponder on UAL 175 was NOT turned "Off" (There is no "Off" on the control panel for this jet's
transponder...... only what's called a "Standby" or "STBY" position....it has the same effect though, the transponder stops transmitting).
On UAL 175 the transponder code was changed. So when the original four-digit code was "scrambled" to other random four numbers, the Air
Traffic Control computers at FAA dropped out the Flight Plan information. That hijacker must have thought he was "clever", but he apparently didn't
realize that even with a random code, the transponder return would still show up on Radar, just with no identifying information as to flight number,
What DID show up on Radar was an easy to track return, and it also included the altitude information, since it will continue to squawk Mode C.
In any case, the transponder code being changed PROVES a human was there to do it....the other three airplanes prove that a human switched their
transponders to STBY.
Here, take a look.....although it's a diagram (typically used in training materials) and not a photo, this is representative of the type of "control
head" panel that is installed in Boeings to operate the transponders (there are two, for redundancy in case one fails in flight):
Knob on left, is obvious I think. The STBY position is what I am talking about....no "Off".
TEST is spring-loaded, so it's momentary. XPDR is just "On", and in this particular configuration, will not transmit Mode C altitude info. I know
this, because in this set-up the next position (TA) is "Traffic Advisory" and that's part of the TCAS (Traffic Collision Avoidance System) that is now
mandatory almost everywhere in the world. As part of the TCAS, altitude information must be operational, as the transponders "talk" to each other and
compare position and altitude.
TA/RA adds the "Resolution Advisory" portion of TCAS....that means it will then coordinate with the other airplane by issuing verbal and visual
commands to avoid a collision.
The center round knobs are two concentric that rotate to change the four digits in the display. The knob "L R" is obvious for the two transponders,
"Left" or "Right" (or "1" and "2").
The little toggle switches are just for the TCAS display parameters, as shown on the pilot's instruments on the forward instrument panels.
edit on Sat 21 January 2012 by ProudBird because: (no reason given)