MH370 Timeline - Deviation From Flight Plan

DECODING MH370
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Flight MH370 Timeline - Deviation From Flight Plan

Each stage in the history of Malaysia Airlines Flight MH370 is covered in the Sections below:-
As MH370 turned west for a turn-back across Malaysia, the aircraft was tracked by Military primary radar (shown in this Section) and also civilian primary radar (shown in the Initial response).


Deviation From Flight Plan


Figure 3: History of recorded events

Figure 3: History of recorded events
Source: ATSB, using Ministry of Transport Malaysia data

Malaysian Military Radar

On this page the military radar observations provide a context and background for other events related to flight MH370 during the 'Air Turnback' - from the loss of contact to the last primary radar observation as MH370 was heading towards the Andaman Sea, west of Malaysia.

A 'blip' believed to be MH370 was observed from 1721:13 UTC [0121:13 MYT] to 1822:12 UTC [0222:12 MYT]

A 'blip' is a spot of light on a radar screen indicating the position of a detected aircraft.

01:21:13 MYT
Location: 3.2nm past waypoint IGARI
Heading: Military radar showed the radar return of MH370 turning right but shortly after, making a constant left turn to heading of 273°, flying parallel to Airway M765 to VKB (Kota Bharu).

01:24:57 MYT to 0137:35 MYT
Heading: varied between 8° and 20°
Speed: varied from 451 kt to 529 kt
Height: varied from 31,150 to 39,116 ft.

01:37:59 MYT
Location: parallel to Airway B219 towards VPG (VOR Penang).
Heading: varied from 239° to 255°
Speed: from 532 to 571 kt
Height: between 24,450 ft and 47,500 ft.

01:41:23 MYT

KL ACC Radar Controller made a “blind transmission” to MH370.

There was no response from MH370.


01:52:31 MYT
Location: 10 nm south of Penang Island
Heading: 261°
Speed: 525 kt
Height: 44,700 ft.

02:01:59 MYT to 0203:09 MYT
Location: near Pulau Perak
Heading: 022°
Speed: 492 kt
Height: detected by Military radar in the area of Pulau Perak at altitude 4,800 ft at 0201:59 MYT.
Comment: At 0203:09 MYT the “blip” disappeared.

02:03:23 MYT

Malaysia Airlines ODC sent an ACARS message to MH370, direct to the cockpit printer. The ACARS message requested the crew to contact the HCM ACC immediately. The incoming downlink message at 1803:24 UTC showed the message failed to reach the aircraft. The message was retransmitted (automatically) at least seven times. On each occasion, an automated downlink message by ACARS showed ‘failed’.


02:03:41 MYT

GES initiates a DATA-2 ACARS transmission (uplink), but receives no acknowledgement from the SATCOM. Therefore, the SATCOM Link was lost at sometime between 1707:48 and 1803:41 (UTC).


02:05:11 MYT

GES initiates a DATA-2 ACARS transmission, but receives no acknowledgement from the SATCOM, indicating that there is still no SATCOM link at this time.


02:15:25 MYT to 0222:12 MYT

Location: about 195 nm from Butterworth,

Heading: 285°
Speed: 516 kt

Height: 29,500 ft

02:22:12 MYT
Heading: observed to be heading towards waypoint MEKAR on Airway N571 when it finally disappeared at 0222:12 MYT, 10 nm after waypoint MEKAR.




02:25:27 MYT

SATCOM Log-On, initiated from the aircraft terminal.

  1. This is the first ‘handshake’.
  2. This marks the end of the link lost period that began at sometime between 1707:48 and 1803:41.
  3. This log-on request suggests that whatever caused the SATCOM link loss to occur between 1707:48 and 1803:41 had been reversed.


02:25:34 MYT

The SATCOM link becomes available (for both voice and data - Class 3) once more and normal SATCOM operation resumes (except that there is no Data-2 ACARS traffic).

No Flight ID was sent to the GES during the Log-On. This implies that the SDU stopped receiving a valid Flight ID from the AIMS at sometime between 1642:04 and 1825:00.

The possible reasons for the link loss and the subsequent Log-On that took place at 1825:00 have been investigated and are detailed in Table 2.5A. There are many quite complicated scenarios that could have caused the 1825:00 Log-On. However, the most likely reason is a power interrupt to the SATCOM avionics, of a duration greater than 22 minutes (the time between events 7 and 9) and less than 78 minutes (the time between events 6 and 9).


02:27:03 MYT

The IFE sets up a Data-3 ground connection (X.25 circuit) over SATCOM for an SMS/e-mail application after the SATCOM link is re-established.


02:28:05 MYT

The IFE sets up a Data-3 ground connection (X.25 circuit) over SATCOM for a BITE application after the SATCOM link is re established.


On the day of the disappearance of MH370, the Military radar system recognised the ‘blip’ that appeared west after the left turn over IGARI was that of MH370. Even with the loss of SSR data, the Military long range air defence radar with Primary Surveillance Radar (PSR) capabilities affirmed that it was MH370 based on its track behaviour, characteristics and constant/continuous track pattern/trend. Therefore, the Military did not pursue to intercept the aircraft since it was ‘friendly’ and did not pose any threat to national airspace security, integrity and sovereignty.

Source: Safety Investigation Report MH370/01/2018 1.1.3 Diversion from Filed Flight Plan 1) Malaysian Military Radar


This Timeline has been created by deconstructing official documents and linking these extracts in a way which simulates a chronological sequence and facilitates access to further detail and explanatory notes for time-related events in the narrative of Malaysia Airlines flight MH370.