Safety Investigation Report 2018:3 Findings and Conclusion/3.1 Findings/3.1.5
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SAFETY INVESTIGATION REPORT
Safety Investigation Report MH370/01/2018
This page contains an extract from the Safety Investigation Report MH370/01/2018 and Appendices released by The Malaysian ICAO Annex 13 Safety Investigation Team for MH370, and dated 2 July 2018.
SAFETY INVESTIGATION REPORT
MH370 (9M-MRO)
3.1.5 Satellite Communications
- 1) Throughout the flight of MH370 the aircraft communicated through the Inmarsat Indian Ocean Region (IOR) I-3 Satellite and the Ground Earth Station (GES) in Perth, Australia.
- 2) At 1707 UTC (07 March 2014), the SATCOM system was used to send a standard ACARS report, normally sent at every 30 minutes. The ACARS reports expected at 1737 UTC and subsequently were not received. The next SATCOM communication was a log-on request from the aircraft at 1825 UTC, followed by two IFE Data-3 channel setups. From that point until 0011 UTC (08 March 2014), SATCOM transmissions indicate that the link was available, although not used for any voice, ACARS or other data services apart from two unanswered ground-to-air telephone calls. At 0019 UTC, the Airborne Earth Station (AES) initiated another log-on request. This was the last SATCOM transmission received from the AES.
- 3) Data from the last seven ‘handshakes’ were used to help establish the most probable location of the aircraft. Both the initial log-on request and the hourly ping have been termed as a ‘handshake'. Two unanswered ground-to-air telephone calls at 1839 and 2313 UTC (07 March 2014) had the effect of resetting the activity log and hence increased the period between the ground initiated ‘handshakes’.
- 4) The two Log-Ons, at 1825 UTC (07 March 2014) and 0019 UTC (08 March 2014), were initiated by the aircraft most likely due to power interruptions to the SATCOM avionics.
- 5) The power interruption leading up to 1825 UTC was probably due to power bus cycling, the reason for it being unknown. The power interruption leading up to 0019 UTC was probably due to low fuel at this time resulting in the loss of both engines and their respective generators. There was probably enough fuel for the APU to start up and run long enough for its generator to power the SATCOM avionics (SATCOM AES) to initiate a log-on request.
Comments and Notes