The folks back at their 'headquarters' have the ability to communicate with the flight crew through what is called the ACARS system. The folks back at 'headquarters' can monitor/down load all sorts of flight data. And if the 'ground controllers' with a 'satellite link' to the aircraft via Satcom have that aircraft's individual identifier code ALONG WITH its particularly assigned computer 'Password', the ground controllers can CHANGE the aircraft's flight plan IN MID-AIR! And with this capability comes the ability to LOCK OUT the flight crew from disengaging the AUTOPILOT by altering the 'logic gates' within those on-board computers.
The bit about "logic gates" is 100% pure technobabble and an absolutely diagnostic sign that the writer
doesn't know what he's talking about and is tossing a word salad of terms hastily Googled up.
A gate is simply a circuit which receives two or more inputs and provides a single output which is a logical function of the inputs, e.g., AND, OR, NAND (AND with the output inverted), NOR, XOR and so forth. These can in turn be connected together to produce more complex functions or even to form a circuit which can store a logical value (two NAND or NOR gates can be cross-coupled to form an S-R flip-flop, which can be kicked into a set or reset state by pulsing one input or the other and which will hold that state until it is kicked again). With additional gates and perhaps some passive components it's possible to construct clocked flip-flops, e.g., J-K or D flip-flops, which will transfer a state based on a logical function of one or more inputs to its output on receiving a pulse on a separate clock input and retain that state until again clocked or reset.
These built-up functional blocks can themselves be built up into more complex circuits which perform various useful functions, for example, adders, value comparators, arithmetic logic units and various kinds of encoders and decoders were implemented as integrated circuits in TTL, to mention a thoroughly obsolete technology.
These even larger functional blocks can in turn be assembled into yet larger systems, such as a general-purpose microprocessor. In fact, projects involving building up a primitive MPU from small-scale integrated circuits- gates- have been produced in kit form as an educational tool, and designing a simple CPU using SSI logic chips is sometimes given as an assignment to electrical engineering students.
A CPU, reduced to its most fundamental components,
is a large array of gates, interconnected to synthesize the logical functions needed for the CPU to operate.
The "altering the logic gates' claim is tantamount to a claim that a CPU will alter its own basic internal circuitry on command. The only likely explanation for this claim is that the claimant is utterly ignorant of the internal workings of any CPU at any level, as well as completely clueless about how ICs are fabricated.
What this sort of egregious misuse of technical language accomplishes is twofold:
1. It proves conclusively that the writer really doesn't know what s/he is talking about.
2. It makes
real techies wet their pants laughing.
I might also mention that the possibility of remote takeover of a 767 by using the ACARS system to uplink waypoint data to the FMS was examined by forum member
apathoid in his
paper on remote takeover scenarios and found very wanting. Apparently
911-investigator has not bothered to read this very informative essay or rejects it for no adequately specified reason.
So we now have a clear view of the sort of sources
911-investigator is relying on in constructing his/her putative action-movie script: agenda-driven ignoramuses/liars posting on the PffT board and professional conspiracy-mongers, with knowledgeable sources nowhere to be found.
That sort of thing might seem good enough if one's entire knowledge of how the world works is derived from the fantasies of TV and movie scriptwriters, but it surely won't do for anyone better-informed.
