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Khamis, 21 Mei 2015

5249. MH370. Communication lost. From Wiki.

Communication lost

External video
 ATC conversations with Flight 370 Audio recordings of conversations between ATC and Flight 370 from pre-departure to final contact (00:25 – 01:19).
The aircraft's final automated position report and last transmission using the Aircraft Communications Addressing and Reporting System (ACARS) protocol was sent at 01:07;[5]:2[45][46]:36 among the data provided in the message was total fuel remaining—43,800 kg (96,600 lb).[47]:9 The final verbal contact with air traffic control occurred at 01:19:30, when Captain Shah[39]:21 acknowledged a send-off by Lumpur Radar to Ho Chi Minh ACC:[d][39]:2[44][48]
[Lumpur Radar] "Malaysian three seven zero, contact Ho Chi Minh one two zero decimal nine. Good night."
[Flight 370] "Good night. Malaysian three seven zero."
The crew was expected to contact air traffic control in Ho Chi Minh City as the aircraft passed into Vietnamese airspace, just north of the point where contact was lost.[49][50] The captain of another aircraft attempted to reach the crew of Flight 370 "just after [01:30]"[51] using the international distress frequency to relay Vietnamese air traffic control's request for the crew to contact them; the captain said he was able to establish contact, but only heard "mumbling" and static.[51] Calls made to Flight 370's cockpit at 02:39 and 07:13 were unanswered but acknowledged by the aircraft's satellite data unit.[5]:18[46]:40


Brown background with white lines, dots, and labels depicting air routes, waypoints, and airports. Label in the top of the image reads: "Military radar plot from Pulau Perak to last plot at 02:22H." Green specks form a trail from bottom centre to left centre that was Flight 370. As the caption explains, the path is in two parts, with a white circle around the blank area between them and appears to highlight a section where the aircraft was not tracked by radar. Label at left end of flight path reads: "Time-02:22H 295R 200nm from Butterworth AB"
Data from Malaysian military radar showing Flight 370 (green) crossing the Strait of Malacca and Andaman Sea to where it was last seen by radar. The left of the two segments of the flight track follows air route N571 between waypoints VAMPI and MEKAR; the white circle appears to highlight a section where the aircraft was not tracked by radar.
At 01:20:31, Flight 370 was observed on radar at the Kuala Lumpur ACC as it passed the navigational waypoint IGARI (6°56′12″N 103°35′6″E) in the Gulf of Thailand; five seconds later, the Mode-S symbol disappeared from radar screens.[39]:2 At 01:21:13, Flight 370 disappeared from the radar screen at Kuala Lumpur ACC and was lost about the same time on radar at Ho Chi Minh ACC, which claims the aircraft was at the nearby waypoint BITOD.[39]:2[44] Air traffic control uses secondary radar, which relies on a signal emitted by a transponder on aircraft; therefore, after 01:21 the transponder on Flight 370 was no longer functioning. The final data from the transponder indicated the aircraft was flying at its assigned cruise altitude of flight level 350[c] and was travelling at 471 knots (872 km/h; 542 mph) true airspeed.[52] There were few clouds around this point and no rain or lightning nearby.[39]:33–36 Later analysis estimated that Flight 370 had 41,500 kg (91,500 lb) of fuel when it disappeared from secondary radar.[39]:30
At the time the transponder stopped functioning—01:21:13—military radar showed Flight 370 turning right, but "almost immediately"[39]:3 the plane began a left turn to a south-westerly direction.[39]:3 From 01:30:35-01:35, military radar showed Flight 370 at 35,700 ft (10,900 m)[e] on a 231° magnetic heading, with a ground speed of 496 knots (919 km/h; 571 mph).[39]:3 Flight 370 continued across the Malay Peninsula, fluctuating between 31,000–33,000 ft (9,400–10,100 m) in altitude.[39]:3 A civilian primary radar at Sultan Ismail Petra Airport with a 60 nmi (110 km; 69 mi) range made four detections of an unidentified aircraft between 01:30:37 and 01:52:35; the tracks of the unidentified aircraft are "consistent with those of the military data."[f][39]:3-4 At 01:52, Flight 370 was detected passing just south of Penang Island. From there, the aircraft flew across the Strait of Malacca to or close to the waypoint VAMPI, passing over Pulau Perak at 02:03, after which it flew along air route N571 to waypoints MEKAR, NILAM, and possibly IGOGU.[5]:3, 38 The last known location, from and near the limits of Malaysian military radar, was at 02:22, 10 nautical miles (19 km; 12 mi) after passing waypoint MEKAR[39]:3, 7 and 200 nmi (370 km; 230 mi) northwest of Penang at an altitude of 29,500 ft (9,000 m).[53][54]
Because of sensitivity about revealing military radar capabilities, countries in the region where Flight 370 disappeared were reluctant to release information they may have collected from military radar. Despite possibly flying near or over the northern tip of Sumatra,[44] Indonesia—which has an early warning radar system—has publicly denied sighting Flight 370 on radar after contact was lost, although the Indonesian military did track Flight 370 earlier when en route to waypoint IGARI.[39]:4[55] Thailand and Vietnam also detected Flight 370 on radar before the transponder stopped working, but not afterwards.[39]:4–5 No radar contact was detected by Australia, including the JORN over-the-horizon radar system, which was believed to be looking north to detect illegal migrants and not west over the Indian Ocean where Flight 370 is presumed to have flown based on satellite communications.[56]

Satellite communication resumes

At 02:25, the aircraft's satellite communication system sent a "log-on request" message—the first message on the system since the ACARS transmission at 01:07—which was relayed by satellite to a ground station, both operated by satellite telecommunications company Inmarsat. After logging on to the network, the satellite data unit aboard the aircraft responded to hourly status requests from Inmarsat and two ground-to-aircraft phone calls, at 02:39 and 07:13, which went unanswered by the cockpit.[5]:18[46] The final status request and aircraft acknowledgement occurred at 08:10. The aircraft sent a log-on request at 08:19:29 which was followed, after a response from the ground station, by a "log-on acknowledgement" message at 08:19:37. The log-on acknowledgement is the last piece of data available from Flight 370. The aircraft did not respond to a status request from Inmarsat at 09:15.[5][46][57][58]

Response by air traffic control

Background is mostly water (blue), at the boundary of the South China Sea and Gulf of Thailand with the extreme southern tip of Vietnam in the upper right and a part of the Malay Peninsula at the Malaysia-Thailand border in the bottom left corner. Numerous air routes and a few waypoints are displayed, with some labelled, and the flight path taken by Flight 370 is shown in bright red. The boundaries of flight information regions are shown. The flight path goes from the bottom just left of centre going north near air route R208, crossing from FIR Kuala Lumpur into FIR Singapore but there is a note that air traffic control along R208 through FIR Singapore is provided by Kuala Lumpur ACC. A label notes where Flight 370 disappeared from primary radar just before turning slightly to the right at waypoint IGARI, which is along the boundary between FIR Singapore and FIR Ho Chi Minh, and the aircraft begins to follow route M765 towards waypoint BITOD. About halfway between IGARI and BITOD, Flight 370 makes sharp turn about 100° to the left, now heading northwest, and travels a short distance before making another left turn and heads southwest, crossing back over land near the Malaysia-Thailand border and flies close to air route B219.
Flight Information Regions in the vicinity of where Flight 370 disappeared from secondary radar. Kuala Lumpur ACC provides ATC services on two routes, located within FIR Singapore, between Malaysia and Vietnam. (Air routes are depicted as roughly 5 nmi / 8–10 km wide, but vary in width, with some as wide as 20 nmi / 30–35 km.)
At 01:38, Ho Chi Minh Area Control Centre (ACC) contacted Kuala Lumpur Area Control Centre to query the whereabouts of Flight 370 and informed them that they had not established verbal contact with Flight 370, which was last detected by radar at waypoint BITOD. The two centres exchanged four more calls over the next 20 minutes with no new information.[44][59]
At 02:03, Kuala Lumpur ACC relayed to Ho Chi Minh ACC information received from Malaysia Airlines' operations centre that Flight 370 was in Cambodian airspace. Ho Chi Minh ACC contacted Kuala Lumpur ACC twice in the following eight minutes asking for confirmation that Flight 370 was in Cambodian airspace.[44] At 02:15, the watch supervisor at Kuala Lumpur ACC queried Malaysia Airlines' operations centre, which said that it could exchange signals with Flight 370 and that Flight 370 was in Cambodian airspace.[59] Kuala Lumpur ACC contacted Ho Chi Minh ACC to query that the planned flight path for Flight 370 passed through Cambodian airspace. Ho Chi Minh ACC responded that Flight 370 was not supposed to enter Cambodian airspace and that they had already contacted Phnom Penh ACC (which controls Cambodian airspace), which had no contact with Flight 370.[44] Kuala Lumpur ACC contacted Malaysia Airlines' operations centre at 02:34, inquiring about the communication status with Flight 370, and were informed that Flight 370 was in a normal condition based on a signal download and that it was located at 14°54′00″N 109°15′00″E.[44][59] Later, another Malaysia Airlines aircraft, Flight 386 bound for Shanghai was requested by Ho Chi Minh ACC to attempt to contact Flight 370 on the Lumpur Radar frequency—the frequency on which Flight 370 last made contact with Malaysian air traffic control—and on emergency frequencies, but without success.[44][60]
At 03:30, Malaysia Airlines' operations centre informed Kuala Lumpur ACC that the locations it had provided earlier were "based on flight projection and not reliable for aircraft positioning."[44] Over the next hour, Kuala Lumpur ACC contacted Ho Chi Minh ACC asking whether they had contacted Chinese air traffic control. At 05:09, Singapore ACC was queried for information about Flight 370. At 05:20, an undisclosed official—identified in the preliminary report released by Malaysia as "Capt [name redacted]"—contacted Kuala Lumpur ACC requesting information about Flight 370; he opined that, based on known information, "MH370 never left Malaysian airspace."[44]
The watch supervisor at Kuala Lumpur ACC activated the Kuala Lumpur Aeronautical Rescue Coordination Centre (ARCC) at 05:30, over four hours after communication was lost with Flight 370.[59] The ARCC is a command post at an Area Control Centre that coordinates search-and-rescue activities when an aircraft is lost.

Announcement of disappearance

Malaysia Airlines issued a media statement at 07:24, one hour after the scheduled arrival time of the flight at Beijing, stating that contact with the flight had been lost by Malaysian ATC at 02:40 and that the government had initiated search and rescue operations;[61] the time when contact was lost was later corrected to 01:21.[62] Neither the crew nor the aircraft's communication systems relayed a distress signal, indications of bad weather, or technical problems before the aircraft vanished from radar screens.[26]

Timeline of disappearance

This section lists events during Flight 370. For a timeline of events in the aftermath of its disappearance, see Timeline of Malaysia Airlines Flight 370
Elapsed (HH:MM)TimeEvent
00:008 March7 MarchTake-off from Kuala Lumpur International Airport
00:2001:0117:01Crew confirms altitude of Flight Level 350 (approximately 35,000 ft / 10700 m)[48]
00:2601:0717:07Last ACARS data transmission received;[45][46]:36 crew confirms altitude of Flight Level 350, a second time[48]
00:26–01:2201:07–02:0317:07–18:03Satellite communication link lost sometime during this period.[46]:36
00:3801:1917:19Last Malaysian ATC voice contact
00:4001:2117:21Last secondary radar (transponder) contact at 6°55′15″N 103°34′43″E[3][4]
00:4101:2217:22Transponder and ADS-B no longer operating.
00:4401:2517:25Aircraft deviated from planned route[5]:2
00:4901:3017:30Voice contact attempt by another aircraft, at request of Ho Chi Minh Area Control Centre (HCM ACC); mumbling and radio static heard in reply[51]
00:5601:3717:37Missed expected half-hourly ACARS data transmission[45]
00:5701:3917:38HCM ACC contacts Kuala Lumpur ACC (KL ACC) to inquire about Flight 370. HCM ACC tells them that verbal contact was not established and Flight 370 disappeared from its radar screens near BITOD waypoint. KL ACC responded that Flight 370 did not return to its frequency after passing waypoint IGARI.[39]:2[44]
01:0501:4617:46HCM ACC contacts KL ACC again, inform them radar contact was established near IGARI, but lost near BITOD and that verbal contact was not established.[44]
01:1601:5717:57HCM ACC informs KL ACC that there was no contact with Flight 370, despite attempts on many frequencies and aircraft in the vicinity.[44]
01:2202:0318:03Malaysia Airlines dispatch centre sent a message to the cockpit instructing pilots to contact Vietnam ATC, which was not responded to.[63] A ground-to-aircraft ACARS data request, transmitted from the ground station multiple times between 02:03-02:05, was not acknowledged by the aircraft's satellite data unit.[46]:36–39
01:2202:0318:03KL ACC contacts HCM ACC and relays information from Malaysia Airlines' operations centre that Flight 370 is in Cambodian airspace.[44]
01:3402:1518:15KL ACC queries Malaysia Airlines' operations centre, which replies that it is able to exchange signals with flight which is in Cambodian airspace.[44]
01:3702:1818:18KL ACC contacts HCM ACC asking them if Flight 370 was supposed to enter Cambodian airspace. HCM ACC replies that Flight 370's planned route did not take it into Cambodian airspace and that they had checked and Cambodia had no information or contact with Flight 370.[44]
01:4102:2218:22Last primary radar contact by Malaysian military, 200 nautical miles (370 km; 230 mi) NW of Penang6°49′38″N 97°43′15″E[5]:3
01:4402:2518:25"Log-on request" sent by aircraft to satellite. Satellite communication link is reestablished after being lost for between 22–68 min.[5]:18[46]:39 Sometimes referred to as the first hourly "handshake" after disappearing from radar.[57][64]
01:5302:3418:34KL ACC queries Malaysia Airlines' operations centre about communication status with Flight 370, but it was not sure if a message sent to Flight 370 was successful or not.[44]
01:5402:3518:35Malaysia Airlines' operations centre informs KL ACC that Flight 370 is in a normal condition based on signals from the aircraft and located at 14°54′00″N 109°15′00″E (Northern Vietnam) at 18:33 UTC. KL ACC relays this information to HCM ACC.[44]
01:5802:3918:39Ground-to-aircraft telephone call, via the aircraft's satellite link, went unanswered.[5]:18[46]:40
02:4903:3019:30Malaysia Airlines' operations centre informs KL ACC that position information was based on flight projection and not reliable for aircraft tracking. Between 03:30 and 04:25, KL and HCM ACCs query Chinese air traffic control.[44]
04:2805:0921:09Singapore ACC queried for information about Flight 370.[44]
05:4906:3022:30Missed scheduled arrival at Beijing Capital International Airport
05:5106:3222:32Kuala Lumpur Aeronautical Rescue Coordination Centre (ARCC) is activated.[39]:2
06:3207:1323:13Ground-to-aircraft telephone call placed by Malaysia Airlines,[63] via the aircraft's satellite link, went unanswered.[5]:18[46]:40
06:4307:2423:24Malaysia Airlines issues a press statement announcing that Flight 370 is missing[62]
07:3008:118 MarchSixth and last successful automated hourly handshake with Inmarsat-3 F1[57][65]
07:3808:19:2900:19:29"Log-on request" sent by aircraft to satellite (sometimes referred to as a "partial handshake")[66][67] believed to have occurred when emergency power restarted the SDU shortly after fuel exhaustion and loss of power.[5]:18, 33[46]:41
07:3808:19:3700:19:37After the ground station responded to the log-on request, the aircraft replied with a "log-on acknowledgement" transmission at 08:19:37.443. This is the last transmission received from Flight 370.[5]:18[46]:41
08:3409:1501:15Aircraft did not respond to a scheduled, hourly handshake attempt by Inmarsat.[46]:41[57]

Presumed loss

On 24 March, Malaysian Prime Minister Najib Razak appeared before media at 22:00 local time to give a short statement regarding Flight 370, during which he announced:
This evening I was briefed by representatives from the UK Air Accidents Investigation Branch. They informed me that Inmarsat, the UK company that provided the satellite data which indicated the northern and southern corridors, has been performing further calculations on the data. Using a type of analysis never before used in an investigation of this sort...Inmarsat and the AAIB have concluded that MH370 flew along the southern corridor, and that its last position was in the middle of the Indian Ocean, west of Perth. This is a remote location, far from any possible landing sites. It is therefore with deep sadness and regret that I must inform you that, according to this new data, flight MH370 ended in the southern Indian Ocean.[17]
Just before Najib spoke at 22:00 MYT, an emergency meeting was called in Beijing for relatives of Flight 370 passengers.[17] Malaysia Airlines announced that Flight 370 was assumed lost with no survivors. It notified most of the families in person or via telephone, and some received the following SMS (in English and Chinese):[17]
Malaysia Airlines deeply regrets that we have to assume beyond any reasonable doubt that MH370 has been lost and that none of those on board survived. As you will hear in the next hour from Malaysia's Prime Minister, we must now accept all evidence suggests the plane went down in the Southern Indian Ocean.[13][14][15]
On 29 January 2015, the Director General of the Department of Civil Aviation Malaysia, Azharuddin Abdul Rahman, announced that the status of Flight 370 would be changed to an "accident", in accordance with the Chicago Convention on International Civil Aviation:[1]
We have concluded that the aircraft exhausted its fuel over a defined area of the southern Indian Ocean, and that the aircraft is located on the sea floor close to that defined area. This is a remote location, far from any possible landing sites. It is also an area with adverse sea conditions with known depths of more than 6,000 metres. After 327 days...and based on all available data as well as circumstances mentioned earlier, survivability in the defined area is highly unlikely....On behalf of the Government of Malaysia, we officially declare Malaysia Airlines flight MH370 an accident in accordance with the Standards of Annexes 12 and 13 to the Chicago Convention and that all 239 of the passengers and crew onboard MH370 are presumed to have lost their lives.[1]
If the official assumption is confirmed, at the time of its disappearance Flight 370 was the deadliest aviation incident in the history of Malaysia Airlines (surpassing the 1977 hijacking and crash ofMalaysian Airline System Flight 653 that killed all 100 passengers and crew on board) and the deadliest involving a Boeing 777, surpassing Asiana Airlines Flight 214 (3 fatalities).[34][35] In both of those categories, Flight 370 was surpassed 131 days later by Malaysia Airlines Flight 17, another Boeing 777-200ER, which was shot down on 17 July 2014, killing all 298 persons aboard.[36]

Reported sightings

The news media reported several sightings of a plane that fit the description of the missing aircraft. For example, on 19 March 2014, CNN reported that "several people on the ground or at sea claimed they saw Malaysia Airlines Flight 370 before it went missing after its post-midnight takeoff from Kuala Lumpur on March 8. The purported eyewitnesses include fishermen, an oil rig worker and islanders in an atoll. Some even alleged they saw it crash. While none of their claims have been substantiated, their assertions add to the ongoing mystery of the missing Boeing 777 and the 239 people aboard."[68]
Two days later, the London-based Daily Mail reported that "a Malaysian woman on a flight across the Indian Ocean claimed to have seen an aircraft in the water near the Andaman Islands on the day the jet disappeared."[69] Three months later, the London Telegraph reported that "a British woman sailing with her husband across the Indian Ocean from India to Thailand has claimed she may have seen the missing Malaysia Airlines plane on fire. Katherine Tee, 41, was on night watch on March 7-8 but said she did not report the sighting until Sunday because she was having marital problems and thought she was losing her mind."[70]

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