Aaargh! Got the I-4 habits on me... but anyways...
Quoting WarrenPlatts (Reply 45): Also, keep in mind that the logoff did not have to happen right at 17:07--it could have happened somewhat later; e.g., before the logoff, there were several hiatuses in activity, such as 16:29 to 16:41, 16:43 to 16:55, 16:05 to 17:05. So the logoff very well could have happened within the IOR/POR overlap zone, that I claim is actually covered by POR. |
1. Inmarsat has not provided information that the aircraft ever logged onto
POR.
2. In satcom, hiatuses of activity does not mean it's logged off.
3. 1629 - 1641, if it logged to
POR, it would have to log onto
IOR again. No logon request on recommencement of communication with
IOR.
4. 1643 - 1655, if it logged to
POR, it would have to log onto
IOR again. No logon request on recommencement of communication with
IOR.
5. 1656 - 1705, if it logged to
POR, it would have to log onto
IOR again. No logon request on recommencement of communication with
IOR.
6. The ground will try to keep open the session channel that is idle or missing, for about 20 minutes (unfortunately, any billable payload being sent that is not received, will continue to be resent, and counted as volume upload, we call this the "Inmarsat nasty surprise" when the bill comes).
7. From 18:03:41 to 18:05:59, 72 machine attempts made from the ground to communicate with the aircraft's satcom. If it logged off there, it would have logged on elsewhere (
POR) and those attempts would not exist.
8. Don't you think Inmarsat would have known about logon to
POR?
Quoting WarrenPlatts (Reply 45): Remember? Instead of drawing full ping rings, they cut it into two arcs with a gap centered on the equator because if the aircraft was on the LOP within the gap, it would have been picked up by POR. Which it was not--then. But earlier in the flight, it would have been within POR's coverage area, and so would have picked up the 9M-MRO's handshake signals. |
Again... If it was picked up by
POR, Inmarsat who is now trying extremely hard to market this so-called "new" capability of providing free marketing, would have known, and would have revealed that.
The gap in the 40deg elevation LOP provided, does
not show a gap centered around the equator. The gap north of the equator is much larger than the gap south of the equator. The arc to the south starts at about 5S latitude, while the north starts at about 20N latitude.
Quoting WarrenPlatts (Reply 45): That the recent release of the "raw" Inmarsat data does not mention the fact that 9M-MRO was communicating with POR should not be surprising, as the "explanations"--such as they are--are very terse, and leave a lot to the imagination. |
It does not, unless one wants it to be.
Quoting Pihero (Reply 47): AFAIK and in view of our experience following the A350 test flights, the FR24 sampling rates for GS and position vs altitude are different. Basically some 20 seconds for altitude. |
For FR24 yes. If the data feeder to FR24 was using the FR24 supplied dongle, the data would be about less than that. If the data feeder was using
ADS-B receiver that is not the FR24 dongle, the sampling rates would be much higher, and that every position has it's altitude tag. This is what I've questioned from day 1, who is the feeder, what is he/she using, if not the FR24 dongle receiver, does he/she have the log, if yes, is the log set at the maximum resolution (2 per secs, but the log would be about 1 per 2 secs instead) or bare minimum (eg: 1 per minute), and would contain a lot more info.
What we're seeing is the FR24 server logs, not the feeder logs. We need the latter.
Quoting Pihero (Reply 47): It goes a lot further than that : One has to program the FMGS to do an autoland, switch both A/Ps on during the approach, select the IAS required for each flap selection (which is very very manual ), lower the landing gear... not even mentioniong the aircraft re-configuration and Checklists...
Autoland is just that . |
Agree. So the argument "if they were planning to land, the autoland should take care of it without human intervention once programmed into the box" is nothing but fiction/misconception.
Quoting lancelot07 (Reply 48): And if the CB is replaced, a reasonably quick start up procedure will follow automatically ? So the system will be operational again in -say- 1 minute or less ? And it will perform a logon immediately ? |
On power up (or power restoration), it would take the ARINC429 feed for position (or its own
GPS receive function module, available on some Inmarsat aircraft antennas), determine where it is and where the nose was pointing and the speed, steer the beam to the satellite, pre-adjust the transmission frequency for doppler, and then request a logon. Yes, it should take less than 1 minute.
Quoting lancelot07 (Reply 48): I wonder if it can be shut off and back on from within the cockpit ? Guess not, but i don't know. |
From the cockpit, to shut off the satcom and switch it back on is, turn the power to the left
AC bus off, and on.
A LOT of things on the aircraft would be affected if you do this.
Quoting lancelot07 (Reply 48): Somehow, i cannot imagine a 777 flying upside down in a level flight at cruise speed for a substantial period of time. |
Me neither...