Timeline/NIO-SIO

MH370 DECODED
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After MH370 turned south toward the South Indian Ocean the aircraft continued flying until running out of fuel.
What we know is limited to data from some satellite communications as shown in this Section

North Indian Ocean to Southern Indian Ocean

From 2:40 MYT to End of Flight Saturday, 8 March 2014
(18:40 UTC Friday, 7 March 2014 to End of Flight)


3. Other Satellite Communications

After the successful log-on which commenced at 0225:27 MYT there were a series of automated communications, and two unsuccessful telephone calls from Malaysia Airlines.

Because the SATCOM was logged-on, the ground station periodically communicated with it to check that it was still logged on. These automated transmissions should occur approximately every hour.

However, the two telephone calls using the satellite system had the effect of resetting the timer at the ground station, so the 'handshakes' initiated by the ground station were not one hour apart.

The Table below shows the sequence of handshakes and phone calls. The metadata associated with the transmissions for each 'handshake' enabled Investigators to calculate the distance of the aircraft from the satellite at the time of each event. This is shown as a series of concentric rings in the diagram below right. The Time on each ring is UTC.


Table 1.9B - SATCOM ‘Handshakes’
SATCOM TRANSMISSIONS TIME
UTC MYT*
1. Aircraft departed KLIA 1642:04 0042:04
2. Last ACARS transmission 1707:48 0107:48
3. 1st handshake - log-on initiated by the aircraft 1825:27 0225:27
4. Unanswered ground-to-air telephone call 1839:52 0239:52
5. 2nd handshake initiated by ground station 1941:00 0341:00
6. 3rd handshake initiated by ground station 2041:02 0441:02
7. 4th handshake initiated by ground station 2141:24 0541:24
8. 5th handshake initiated by ground station 2241:19 0641:19
9. Unanswered ground-to-air telephone call 2313:58 0713:58
10. 6th handshake initiated by ground station 0010:58* 0810:58
11. 7th handshake - log-on initiated by the aircraft 0019:29* 0819:29
12. Aircraft did not respond to ‘handshake’ from Satellite Earth Ground Station 0115:56* 0915:56
*08 March 2014

Table 1.9B - SATCOM ‘Handshakes’


Source: Malaysian ICAO Annex 13 Safety Investigation Team for MH370, 02 July 2018, Safety Investigation Report MH370/01/2018

Note: Table 1.9B, when published, showed times rounded to the nearest minute. The above version has been updated to include seconds, so that each time can be linked to the correct event in the Timeline. No other data has been changed. The two versions can be seen together here.

ATSB MH370 - Definition of Underwater Search Areas 2014 Figure 18

Figure 18: BTO ring solutions for 9M-MRO
Source: MH370 - Definition of Underwater Search Areas[1], Australian Transport Safety Bureau, 2014.

Note: Each yellow arrow points to a 'ring', using the time as a label. The arrow does not indicate the position of MH370 at that time.


5. A Possible Flight Path

There are many variables to consider when defining the time when MH370 turned south. Investigators have worked hard to refine their mathematical models so that they can predict more accurately where the flight ended.

Obviously, we do not know the exact time that a turn commenced. There have been many attempts to reconstruct a flight path using an early turn; a late turn; or some time in-between. Each solution must still place the aircraft on one of the seven arcs at the time of the relevant satellite communication.

An aircraft can also make different types of turn - gentle and level is normal for passenger flights; or steeply banked; maybe with some acceleration through the turn; or a change of altitude. There are many possibilities, including whether the turn was manually controlled or executed by the autopilot.

One of the valid flight paths is shown in the diagram opposite. This one was created by engineers from Inmarsat[2] who did the original calculations with the values of Burst Timing Offset and Burst Frequency Offset. Without this innovative analysis of the metadata we would have absolutely no idea where MH370 went after flying beyond Malaysia's military radar coverage.

The flight path shown here is 'indicative' - it represents a likely end-of-flight path in a southerly direction with its' heading changing from 186° to 180° by the end of the flight[2].


Note: Although MH370 was close to the northern tip of Sumatra, it likely crossed, or was close to, Indonesian airspace. But there is no radar data from Indonesia.

Figure 17. Example Flight Path.

Figure 17. Example Flight Path.

Source: The Search for MH370[2], Chris Ashton, Alan Shuster Bruce, Gary Colledge and Mark Dickinson (Inmarsat), as published in The Journal of Navigation (2015)


02:40:56 MYT

The GES logs show that the unanswered Ground-to-Air telephony call was cleared by the calling party.


Time:0253:48 MYT

Time:0254:28 MYT

03:41:00 MYT

Log-On Interrogation by the Perth GES, with a response from the SATCOM

  1. This is the second ‘handshake’, whereby the GES inactivity timer has expired and the GES has sent a message to interrogate the status of the SATCOM.
  2. The SATCOM responded normally and the SATCOM link was therefore available at this time.


04:41:02 MYT

Log-On Interrogation by the Perth GES, with a response from the SATCOM

  1. This is the third ‘handshake’.
  2. The SATCOM responded normally and the SATCOM link was therefore available at this time.


05:41:24 MYT

Log-On Interrogation by the Perth GES, with a response from the SATCOM

  1. This is the fourth ‘handshake’.
  2. The SATCOM responded normally and the SATCOM link was therefore available at this time.



06:30 MYT

Malaysia Airlines Flight MH370 departed Kuala Lumpur International Airport at 00:41 MYT Saturday, 8 March 2014 and was expected to land in Beijing at 06:30 MYT. The Flight Plan estimated an elapsed flight time of 5 hours and 34 minutes.



06:41:19 MYT

Log-On Interrogation by the Perth GES, with a response from the SATCOM

  1. This is the fifth ‘handshake’.
  2. The SATCOM responded normally and the SATCOM link was therefore available at this time.


07:00:42 MYT

Malaysia Airlines Operations used ACARS to upload flight plan information for MH371, which is the normal return flight from Beijing to Kuala Lumpur.

The intention of this upload may have been to assist MH370 to return to Kuala Lumpur. Unfortunately, the initiative was unsuccessful.


07:13:58 MYT

Ground-to-air telephony call placed from a number with country code 60 (Malaysia)

  1. Q10 AOC Priority Level.
  2. The Perth GES logs indicate that a good link is likely to have existed at this time.
  3. This call would have been routed to the cockpit and should have resulted in a chime and an incoming visual annunciation on the Audio Control Panels, and, if the appropriate SATCOM page was selected, then also on one or more MCDU.
  4. The GES logs show zero duration, indicating that the call went unanswered. Note that there are two methods for the answering of an incoming call: Either by pressing the relevant Line Select Key on an MCDU, or by keying a microphone.


07:15:02 MYT

The GES logs show that the unanswered Ground to Air telephony call was cleared by the calling party.


08:10:58 MYT

Log-On Interrogation by the Perth GES, with a response from the SATCOM

  1. This is the sixth ‘handshake’.
  2. The SATCOM responded normally and the SATCOM link was therefore available at this time.


08:19:29 MYT

SATCOM Log-On, initiated from the aircraft terminal. This is the seventh ‘handshake’.

  1. For there to have been a Log-On at this time, there must have been a prior loss of the SATCOM link. This link loss must have occurred at some time after 0010:58, when the SATCOM responded to a Log-On interrogation.
  2. This Log-On request suggests that whatever caused the SATCOM link loss to occur had been reversed.


08:19:37 MYT

SATCOM Log-On, successfully completed

  1. The SATCOM link becomes available (for voice and data – Class 3) once more and normal SATCOM operation resumes.
  2. No Flight ID was sent to the GES during the Log-On. This infers that the SDU was still not receiving the Flight ID from AIMS.


09:15:56 MYT

Log-On Interrogation by the Perth GES, with no response from the SATCOM


09:16:06 MYT

Log-On Interrogation by the Perth GES, with no response from the SATCOM.


09:16:15 MYT

Log-On Interrogation by the Perth GES, with no response from the SATCOM.





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