Timeline/Pre-Flight/1250:19 UTC

Malaysia Airlines Flight MH370 Timeline - Pre-Flight

Pre-Flight

KLIA to South China Sea

South China Sea to Straits of Malacca

Straits of Malacca to Andaman Sea

Andaman Sea to North Indian Ocean

North Indian Ocean to Southern Indian Ocean

Event Summary

 20:50:19 MYT Friday, 7 March 2014

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The Satellite Data Unit (SDU) on Malaysia Airlines Boeing 777 registered 9M-MRO initiated the first of several Log-On requests to the Inmarsat satellite communications system.
The transmission was relayed via Inmarsat's Pacific Ocean Region I-3 satellite to the Ground Earth Station (GES) near Perth in Western Australia.

Event Details

1. Safety Investigation Report MH370/01/2018 - Table 1.9C - Chronology of Satellite Communications Ground Station Logs

   ‎

   No.	Time (UTC)	Key Observations - Satellite Ground Station Logs
   1.	1250:19	Prior to take-off, the SATCOM initiates a normal Log-On as Class 1 (data only capable) via the Pacific Ocean Region (POR) I-3 satellite, using the Low Gain Antenna (LGA) subsystem, suggesting that ADIRU (Air Data Inertial Reference Unit) navigation data was not available to the SDU at this time. No flight ID is sent to the GES at this time. This is the first SATCOM activity recorded at the GES since 0802:27, suggesting that the SATCOM was not powered for a period of several hours, whilst the aircraft was on ground. This is quite normal.

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Notes

1. The aircraft systems were powered on before the arrival of the Flight Crew.
2. The SATCOM system would have initiated the Log-On request automatically, and used the Pacific Ocean Region I-3 satellite because that was how it was configured when previously shut down.
3. The Inmarsat Ground Earth Station is located near Perth in Western Australia. This GES communicates with satellites in both the Pacific Ocean Region and the Indian Ocean Region.
4. The data sent did not include a Flight ID because that information had not yet been entered into the system.
5. BFO and BTO data is not available because the first entry in the Data Communication Logs is at 1559:55.413 UTC (2359:55.413 MYT 7 March)
6. The aircraft was on the ground. This event at 1250:19 UTC (2050:19 MYT Friday, 7 March 2014) is the first Satcom activity since 0802:27 UTC (1602:27 MYT Friday, 7 March 2014).

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Disclaimer

Each Event in the Timeline pages has been identified from data in official documents. The details, evidence, supporting documents, references, explanatory notes etc., are provided in Event Details pages such as this. The event Summary is based on that evidence either as a direct quote or as a summary of collated data. Please refer to the actual sources as quoted or by following links to view the data in the context of the original documentation.

Malaysian Time (MYT) is Coordinated Universal Time (UTC) + 8 hours

Satellite Data Unit

Aircraft Registration Number for the Boeing 777 used for Flight MH370. More Info

Ground earth station. A satellite ground station sends or receives data from orbiting satellites. (Source: ATSB)

Coordinated Universal Time

Pacific Ocean Region

Low Gain Antenna

Air Data Inertial Reference Unit

Identification

Flight Identifier, for example MH370

Burst frequency offset. BFO is a measure of the difference between the expected frequency of a satellite transmission and the frequency received at the ground station. (Source: ATSB)

Burst Timing Offset. BTO is a measure of the time taken for a satellite transmission round trip (ground station to satellite to aircraft and back) and allows a calculation of the distance between the satellite and the aircraft. (Source: ATSB)