The discussion prompted by last week’s blog post raised some interesting issues that I think are worth discussing in further detail.
First, I wrote last week that “At 18:22, MH370 vanished from primary radar coverage over the Malacca Strait. Three minutes later—about the amount of time it takes the Satellite Data Unit (SDU) to reboot—the satcom system connected with Inmarsat satellite 3F-1 over the Indian Ocean and inititated a logon at 18:25:27.”
Commenter LouVilla earlier today laid out the issue with more clarity, writing:
MH370 flew out of radar range @18:22.12 UTC. All of a sudden @18:25.27 UTC, the AES sent an Login-Request to the satellite. This are 03:15 Minutes between this two events. When the AES is without power supply for a while and reboots after power is available again the AES needs approximately 02:40 Minutes to sent an Login Request (ATSB Report Page 33). 03:15 minus ~ 02:40 = ~ 35 seconds. So, the perpetrator must activated the left bus again at around 18:22.47 UTC, 35 seconds after MH370 flew out of radar range.
The close sequence of these events does, in my mind, raise the possiblity that they are connected. How would a perpetrator know that he has left radar coverage? Among the possibilites would be a) some kind of radar-energy detector (like that used by automobile speed-trap radar detectors) brought on board by the perpetrators, or b) prior scouting by allied agents. This latter idea would be far fetched for a suicidal pilot but quite feasible for, say, Russia, which spends quite a lot of time probing the radar coverage of its NATO neighbors.
Of course the timing might just be a coincidence.
A second point I’d like to address is the idea that Zaharie or Fariq might have de-powered the satcom by isolating the left AC bus. One problem with this scenario, as I’ve previously mentioned, is that it would be difficult for a pilot to know just what else they would be taking off line in isolating the left AC bus. I later realized that I had underestimated the problem.