Yesterday Writer7 wrote an excellent series of posts analyzing the number-crunching of the satellite data done by aviation reporter Jeff Wise (CNN, Salon) and scientists on Wise's blog. Writer7's fine work culminated with a timeline for the Inmarsat satellite pings from MH-370.
I thought it might be illuminating to plot those satellite pings on the broader MH-370 timeline:
00:30 am - PING #1
00:36 am - Taxiing.
00:41 am - Take-off
00:43 am - PING #2
00:50 am - Climbing from 25,000 to 35,000 feet.
00:55 am - PING #3
01:01 am - Cruising at 35,000 feet.
01:07 am - PING #4, Last routine ACARS data transmission.
01:07 am - MH-370 cockpit to ATC, repeats "Malaysian...370 maintaining level 350" (35,000ft)
01:19 am - "Good Night Malaysian Three Seven Zero"
01:21 am - MH-370 Transponder turns off.
01:22 am - (approx) IGARI waypoint reached, 360 deg. West turn begins.
01:30 am - After Viet ATC asks, nearby plane contacts MH-370, hears "buzz", "mumbling".
01:38 am - Viet ATC informs Malay ATC of situation, neither can contact MH-370.
02:15am - (approx) Last Thai/Malay military radar blip of MH-370, heading NW.
02:25 am - PING #5
02:27 am - PING #6
02:29 am - PING #7
02:40 am - Viet ATC notifies Malaysia Airlines it can't contact MH-370.
03:40 am - PING #8
04:40 am - PING #9
05:40 am - PING#10
06:40 am - PING #11
08:11 am - PING #12
08:19 am - Partial handshake PING from MH-370 to ground station.
This timeline raises a few interesting questions:
1). Between 12:30-1:07, the plane pinged the satellite every 12-13 minutes. In normal flight, should it have continued to do so? No ping at 1:19/1:20 am might suggest ACARS was disabled at or before that time.
2). Why was there a sudden flurry of pings at 2:25, 2:27, and then 2:29...???
3). Why did MH-370 start sending hourly pings at 3:40am (not 2:40am)?
4). Why was there no hourly ping at 7:40am, but instead one at 8:11am?
5). Why did the plane ping a ground station at 8:19am? To indicate what?