Chronology/Radar Observations

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Chronology: Radar Observations

This article presents extracts from the Safety Investigation Report MH370/01/2018 which have been selected because the content is a chronology of events related to Malaysia Airlines flight MH370.

Each event in this chronology has been linked to a Timeline Event in the main Timeline articles on this site. This provides a cross-link or check on the well known events.


Background Notes

After MH370 passed waypoint IGARI the aircraft should have announced it's entry into the Vietnamese FIR by contacting Ho Chi Minh ATC as instructed by Malaysian air traffic control. Instead, the flight diverted west across Malaysia and north west along the Malacca Strait.

During that transit across Malaysia the aircraft was captured by air traffic control primary radar, which they did not notice; and by military primary radar, to which the military did not respond in any way. The military radar tracking data has not been released to the public or independent investigators. The ATC radar data track is shown in a diagram without much detail.

The information available about the radar tracking of an aircraft believed to be MH370 is simply a narrative in the Introduction section of the Safety Investigation Report MH370/01/2018 . Extracts from this section are provided below. Some links to events in the Timeline may have been added.

Radar Observations and the Timeline

Radar tracking provides a context during which other specific events occurred. Two sections in particular are 1) the turnback across peninsula Malaysia and beyond, and 2) the response by air traffic controllers. These are discussed below:-

  1. Turnback across peninsula Malaysia and beyond:

    This section of the flight is presented in two sections of the Flight MH370 Timeline. These are:-

    1. South China Sea to Straits of Malacca
    2. Straits of Malacca to Andaman Sea

    Both periods of time include radar observations by civilian air traffic control primary radar (which went unnoticed) and military primary radar which captured the aircraft but no action was taken because it was deemed to present no threat.


  2. Response by Air Traffic Controllers:

    This section of the Timeline details the sequence of events as air traffic controllers struggled to comprehend that MH370 did not continue towards Beijing through Vietnamese airspace; and while they were wondering where it was and making phone calls and asking questions the evidence of a turnback was in front of them on their radar screen. The 'blip' that represented the 'missing' aircraft was captured by civilian primary radar. Like the military observations there were periods of actual data, periods of 'coasting' - where the radar interpolates a track between actual radar responses - and periods of interrupted data. This is difficult to represent as a chronology (because the observations are not discrete events), but easier to show as a background or context for all the other activities involved in the Initial Response to the 'disappearance' of MH370.




1.1 History of the Flight

1) Malaysian Military Radar

The Military radar data provided more extensive details of what was termed as “Air Turn Back”. It became very apparent, however, that the recorded altitude and speed change “blip” to “blip” were well beyond the capability of the aircraft. It was highlighted to the Team that the altitude and speed extracted from the data are subjected to inherent error. The only useful information obtained from the Military radar was the latitude and longitude position of the aircraft as this data is reasonably accurate.

At 1721:13 UTC [0121:13 MYT] the 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).

Between 1724:57 UTC [0124; 57 MYT] to 1737:35 UTC [0137:35 MYT] the “blip” (a spot of light on a radar screen indicating the position of a detected aircraft) made heading changes that varied between 8° and 20°, and a ground speed that varied from 451 kt to 529 kt. The Military data also recorded a significant height variation from 31,150 to 39,116 ft.

The Military data further identified the “blip” on a heading of 239° at 1737:59 UTC [0137:59 MYT] parallel to Airway B219 towards VPG (VOR Penang). Heading of this “blip” varied from 239° to 255° at a speed from 532 to 571 kt. The height of this “blip” was recorded between 24,450 ft and 47,500 ft.

At 1752:31 UTC [0152:31 MYT] the “blip” was observed to be at 10 nm south of Penang Island on a heading of 261°, speed of 525 kt and at a height of 44,700 ft.

At 1801:59 UTC [0201:59 MYT] the data showed the “blip” on a heading of 022°, speed of 492 kt and altitude at 4,800 ft. This is supported by the “blip” detected by Military radar in the area of Pulau Perak at altitude 4,800 ft at 1801:59 UTC [0201:59 MYT]. At 1803:09 UTC [0203:09 MYT] the “blip” disappeared, only to reappear at 1815:25 UTC [0215:25 MYT] until 1822:12 UTC [0222:12 MYT], about 195 nm from Butterworth, on a heading of 285°, speed of 516 kt and at an altitude of 29,500 ft.

The tracking by the Military continued as the “blip” was observed to be heading towards waypoint MEKAR on Airway N571 when it finally disappeared at 1822:12 UTC [0222:12 MYT], 10 nm after waypoint MEKAR.

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.

Based on the Malaysian Military data, a reconstruction of the profile was conducted on a Boeing 777 simulator. Figure 1.1B (below) in chart form shows the Profile Chart of Data from Malaysian Military Radar. Some of the speed and height variations were not achievable even after repeated simulator sessions.

It was also noted that, in the absence of autopilot or continuous manual control, an aircraft is very unlikely to maintain straight and level flight. Further, it is extremely unlikely for an aircraft to enter and maintain a turn and then return to straight and level flight for any significant period of time.


Figure 1.1B - Profile Chart of Data from Malaysian Military Radar (not to scale).

Figure 1.1B - Profile Chart of Data from Malaysian Military Radar (not to scale).
Source: Safety Investigation Report MH370/01/2018


2) DCA Civilian Radar Data from Kota Bharu - Sultan Ismail Petra Airport Runway

The aircraft diversion from the filed flight plan route was recorded on the DCA radar playback:

  • a) From 1730:37 UTC [0130:37 MYT] to 1744:52 UTC [0144:52 MYT] a primary aircraft target was captured by the Terminal Primary Approach Radar located to the south of the Kota Bharu – Sultan Ismail Petra Airport runway.

  • b) The appearance of an aircraft target on the KL ACC radar display, coded as P3362, was recorded at 1730:37 UTC [0130:37 MYT] but the aircraft target disappeared from the radar display at 1737:22 UTC [0137:22 MYT].

  • c) At 1738:56 UTC [0138:56 MYT] an aircraft target, coded as P3401, appeared on the KL ACC radar display and disappeared at 1744:52 UTC [0144:52 MYT].

  • d) At 1747:02 UTC [0147:02 MYT] an aircraft target, coded as P3415, appeared on the KL ACC radar display but disappeared at 1748:39 UTC [0148:39 MYT], which appeared to be the continuity of the same target.

  • e) At 1751:45 UTC [0151:45 MYT] an aircraft target, coded as P3426, appeared on the KL ACC radar display but disappeared at 1752:35 UTC [0152:35 MYT].

Figure 1.1C (below) shows Diversion from Filed Flight Plan Route (in pictorial form and not to scale).

Figure 1.1C - Diversion from Filed Flight Plan Route - Civilian Radar (in pictorial form and not to scale)

Figure 1.1C - Diversion from Filed Flight Plan Route - Civilian Radar
(in pictorial form and not to scale)

Source: Safety Investigation Report MH370/01/2018 1.1.3 (2)


It has been confirmed by DCA and its radar maintenance contractor, Advanced Air Traffic Systems (M) Sdn. Bhd. (AAT), that it was the 60 nm Terminal Primary Approach Radar, co-mounted with 200 nm monopulse SSR located to the south of Kota Bharu - Sultan Ismail Petra Airport runway, which captured the above-mentioned primary aircraft targets.

Figure 1.1D (below) shows the suitable airports for emergency en-route diversion.


Figure 1.1D - Airports for Emergency Landing along the Flightpath of MH370 (chart not to scale)

Figure 1.1D - Airports for Emergency Landing along the Flightpath of MH370 (chart not to scale)
Source: Safety Investigation Report MH370/01/2018 1.1.3 (2)


Figure 1.1E (below) shows the Filed Flight Plan message of MH370.


Figure 1.1E - Filed Flight Plan message of MH370.

Figure 1.1E - Filed Flight Plan message of MH370.
Source: Safety Investigation Report MH370/01/2018 1.1.3 (2)


Figure 1.1F (below) shows Radar Data Plots (RDP) Tracks from the 60 nm Terminal Primary Approach Radar co-mounted with 200 nm monopulse SSR located to the south of Kota Bharu - Sultan Ismail Petra Airport runway after Diversion and Figure 1.1G (below) shows RDP Tracks from Kuala Lumpur after take-off.

All the primary aircraft targets that were recorded by the DCA radar are consistent with those of the military data that were made available to the Investigation Team.


Note: Figure not included.

Figure 1.1F - Radar Data Plots (RDP) Tracks from the 60 nm Terminal Primary Approach Radar co-mounted with 200 nm monopulse SSR located to the south of Kota Bharu - Sultan Ismail Petra Airport runway after Diversion.
Source: Advanced Air Traffic Systems (M) Sdn. Bhd. (AAT)

Note: Figure not included.

Figure 1.1G - Radar Data Plots (RDP) Tracks from Kuala Lumpur after take-off

Source: Advanced Air Traffic Systems (M) Sdn. Bhd. (AAT)


Reference:

The Malaysia Aeronautical Information Publication [AIP] ENR 1.6 dated 05 June 2008, AIP AMDT 2/2008 on the Provision of Radar Services and Procedures states that, in paragraph 1.1.4:
“In the Kuala Lumpur and Kota Kinabalu FIRs, radar services are provided using the following civil/military ATC Radars:
g) A 60 nm Terminal Primary Approach Radar co-mounted with 200 nm monopulse SSR located to the south of Kota Bharu - Sultan Ismail Petra Airport runway.”.

Figure 1.1H (below) shows the Radar Coverage Chart of Kuala Lumpur and Kota Kinabalu FIRs.


Note: Figure not included.

Figure 1.1H - Radar Coverage Chart of Kuala Lumpur and Kota Kinabalu Flight Information Regions


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4) Kuala Lumpur ACC Radar

KL ACC Radar captured the disappearance of MH370 at 1721:13 UTC [0121:13 MYT]. In interviews with the Duty KL ACC Radar Controller, he stated that he did not notice the “blip” disappearance as MH370 was out of radar coverage and would be in contact with HCM ACC after the transfer of responsibility was effected.

From 1730:37 UTC [0130:37 MYT] to 1752:35 UTC [0152:35 MYT], what appeared to be MH370 was captured on KL ACC primary radar, coded as P3362, P3401, P1415, P3415 and P3426 (P signifies Primary Radar).
Figure 1.1C - Diversion from Filed Flight Plan Route.

The appearance of a “blip” coded as P3362 was recorded at 1730:37 UTC [0130:37 MYT)] but disappeared abruptly at 1737:22 UTC [0137:22 MYT].

At 1738:56 UTC [0138:56 MYT], a “blip” identified as P3401 was tracked by KL ACC but disappeared at 1744:52 UTC [0144:52 MYT].

Shortly after, another “blip” coded as P3451 appeared at 1747.02 UTC [0147:02 MYT] but disappeared at 1748:39 UTC [0148:39 MYT].

At 1751:45 UTC [0151:45 MYT], a “blip” coded as P3426 appeared south of Penang Island but disappeared at 1752:35 UTC [0152:35 MYT].

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