Yes, perhaps because those writing are a bit confused.
Keep in mind that the A/P can be made to "sync up" with the route that is in the FMC, on the Legs Page:
(Note: Based on the color, this is likely from a B737NG. Also because of the Mach number of .78, whereas a B777 is "happier" at M .80 to .84, or thereabouts. But the displays are virtually identical across the Boeing product line, though the instrument panel paint color differs. The light brown/tan for the B757, 767 and 777 product line, usually).
That example shows the "Active Route". At left are the waypoints in sequence, top to bottom. The one in magenta is "Active", or being steered to.
The rest have the magnetic course displayed, the actual direction between each. So you see, there are course changes possible to "program" as each waypoint is passed.
Also you see the distance between them. When the A/P is programmed in the LNAV mode (short for "Lateral Navigation"), then it will follow the route as defined in the FMC. Sequentially following from waypoint to waypoint, unless interrupted, or reaching the end of an "Active Route".
So, this is one of the roll mode options, including the "basic" HDG SEL. Also, HDG HOLD (which just maintains whatever heading you are one when selected). The A/P can also be "told" to capture and track a VOR radial, and a Localizer course too. There are actually a total of nine Roll Modes, but that gets even more confusing and irrelevant to MH370. (Some involve the AutoLand function, for example).
Nah, that was fairly easy to follow Weed Whacker, thanks.
No, it will revert to a basic mode such as heading Hold and altitude hold. The autopilot needs to be disengaged manually once engaged.
This is what I meant when I referred to the AP no longer being able to maintain ,,, well, anything. It cannot maintain altitude, would begin having trouble maintaining speed above stall without a severe nose down , possibly maintain a course, but all of that assumes the FMC and/or AP are powered.
.......Instead of manually operating the plane’s controls, whoever altered Flight 370’s path typed seven or eight keystrokes into a computer on a knee-high pedestal between the captain and the first officer, according to officials. The Flight Management System, as the computer is known, directs the plane from point to point specified in the flight plan submitted before a flight.
So how I interpret this is: The "7 or 8 keystrokes" would be about right for someone typing in a 5-digit fix or waypoint, the pressing the L1 button on the CDU (to move that fix to the first and "active" position), then pressing the 'EXEC' button to execute the command. The airplane would then turn (if on A/P and in the LNAV roll mode) in order to track to the new waypoint.And they withdrew their assertion that another automated system on the plane, the Aircraft Communications Addressing and Reporting System, or Acars, had already been disabled when the co-pilot spoke.
Flight 370’s Flight Management System reported its status to the Acars, which in turn transmitted information back to a maintenance base, according to an American official. This shows that the reprogramming happened before the Acars stopped working. The Acars ceased to function about the same time that oral radio contact was lost and the airplane’s transponder also stopped...
I was wondering how they would know the digits had been typed. assumed they were just guessing.
From what you and WeedWhacker have said, this struck me as odd. Not only are we being told ACARS transmitted the keystroke punches which you didn't think was monitored that way, were we also not informed that Malaysian Air did not subscribe to this type of maintenance download? That would mean that this is be a Boeing procedure. So is Boeing 'spying' on its aircraft worldwide and pilots are unaware of it?
that's what I took from it too. since 2 or 3 of the digits were "secret airline code stuff" ?? but since the data couldn't have been transmitted to the ground, I think the article was just poorly written.
