Three more questions...
- is it known how the BTO data published ("raw data" PDF) were measured? It is evident that the digits are not the whole go and back signal time. Regardless what is substracted to the whole trip of the signal, it have to be at least two different very accurate time stamps: the first when the signal is sent by the GES, the second when it comes back. So, how could be computed the BTO at, for example, 18:25:27,421 (value is 17120 usec)? It is "the end of the link lost period that began at sometime between 17:07:48 and 18:03:41". It is a RX from the aircraft, without any TX from the GES before which could have initiated the RX (and timestamped). 1.431 second later, the GES answers (Log-on confirm), followed by a sequence of 4 TX. When was measured the "17120 usecs"? And between which times?
- is there any possibility that the "activity" of the satellite unit (when it logs on or when it answers a "ping" from the GES) could be "viewed" from the cockpit, even on a sub sub screen of a normally never used display?
- has it been published something accepted or "credible" about the reason of the "re"log at 18:25?
There is a post on the DuncanSteel blog where some infos are written about the communication link, particularly this:
Originally Posted by http://www.duncansteel.com/archives/826#comment-6702
If the “Data Link System Reset” function is selected:
- ATC connection is reset and not re-established.
- Review messages (history) are deleted.
- VHF C is selected as default radio and set to data mode (if plane is on the ground) or voice mode (if plane is in the air)
- HF R is selected as default and set to voice.
- ACARS is set to Auto.
- ADS Emergency is reset to OFF
The Data Communications System is automatically reset after each flight, or 10 minutes after engine shutdown, and when any passenger door is open. Source: B777 Communications Manual.
Is this seems correct? Could it be applied to a passenger door blown (or opened) in flight?
That is five questions, actually...