HONG KONG - Seventeen minutes passed after Malaysia Airlines Flight 370 disappeared from civilian radar screens before air traffic controllers in Vietnam and Malaysia raised any concerns about it, according to a Malaysian government report released Thursday that described confusion and miscommunication in the hours that followed.
The details of delays and miscues came in a preliminary report by Malaysia's chief inspector of air accidents on the investigation into the missing jet, which left only tantalizing clues to its likely whereabouts that were not recognized or understood for days after it disappeared on March 8. Experts eventually concluded that the plane must have fallen into the southern Indian Ocean off the coast of Western Australia, thousands of miles from its planned route to Beijing over the Gulf of Thailand, where searchers initially wasted crucial days on a fruitless hunt.
The hunt for debris or flight recorders from the plane has so far yielded nothing solid, and investigators have said that the final signals from the plane, received by an Inmarsat communication satellite, gave them only a general idea of where the plane probably fell into the ocean. The government report suggested that commercial planes should be tracked constantly throughout their flights, and not just when they are within range of ground radar and their transponders are working, to avert another such baffling loss.
"While commercial air transport aircraft spend considerable amounts of time operating over remote areas, there is currently no requirement for real-time tracking of these aircraft," the report noted. "It is recommended that the International Civil Aviation Organization examine the safety benefits of introducing a standard for real-time tracking."
Malaysian officials have said that the public report issued Thursday was similar to one they had already submitted to the organization.
The report and accompanying documents indicated that the initial search efforts for the missing plane were dogged by miscommunication and mistakes that began while the plane was still in flight - and that appeared to cement initial, mistaken assumptions that the plane had fallen somewhere much closer to the Malaysian peninsula.
The plane took off at 12:41 a.m. from Kuala Lumpur International Airport, bound for Beijing. It disappeared from Malaysian air traffic controllers' radar at 1:21 a.m. local time, when the plane was near airspace managed by controllers in Vietnam. Seventeen minutes later, at 1:38 a.m., the Vietnamese controllers noted that something was amiss and "made a query" to their Malaysian counterparts, the report said.
The investigation revealed that the Malaysia Airlines operations center sowed confusion when it told Kuala Lumpur air traffic control at 2:15 a.m. that the plane's signals showed it was "flying in Cambodian airspace," according to a timeline accompanying the report. At 2:35 a.m., nearly an hour after the plane disappeared from civilian radar, the airline's operations center told the Kuala Lumpur control center that a "signal download" from the plane indicated that it was halfway up the Vietnam coast on its regular flight path.
The Kuala Lumpur controllers passed that information to Vietnam two minutes later, and for the next hour, air traffic controllers in the region tried in vain to contact the plane.
Only at 3:30 a.m. did the airline tell controllers that the information it had given was "not reliable for aircraft positioning," according to the timeline. The Kuala Lumpur Rescue Coordination Center went into action two hours later, after "all effort to communicate and locate the aircraft failed," the report said. The plane was probably still flying at that time, investigators have since concluded.
The investigator's account of actions by air traffic controllers does not mention any effort to contact any of the three Malaysian military bases whose radar systems tracked the aircraft as it veered off course and flew west across the country. In an email accompanying the investigator's report, Hishammuddin Hussein, Malaysia's defense minister, wrote that the "aircraft was categorized as friendly by the radar operator, and therefore no further action was taken at the time."
Hishammuddin did not explain how the military operator made that judgment. Nor did the report explain why the Malaysian military radar installation at Butterworth, which doubles as a civilian air traffic control station, did not take part in communications among air traffic controllers across the region about the missing plane.
Military radar last recorded a trace of the plane at 2:22 a.m., as it was flying west past the Strait of Malacca and out into the ocean, according to a map provided with the investigator's report. Experts believe that the plane made a mystifying turn to the south shortly thereafter.
Hishammuddin wrote that he was told at 10:30 a.m. of the "possible turn-back of the aircraft," and then notified the country's prime minister, Najib Razak, who ordered that searchers look for the plane in the Strait of Malacca, west of the Malaysian peninsula, as well as in the waters east of the peninsula where they were already hunting.
Along with the report and documents, the government released recordings of conversations between air traffic controllers and the pilots of Flight 370. The exchanges were routine and did not appear to reveal anything sinister. The last words heard from the cockpit, at 1:19 a.m. were "Good night, Malaysian Three Seven Zero."
Firm conclusions about the specific causes of Flight 370's disappearance are likely to elude investigators unless the plane's flight recorders are recovered and analyzed. They are believed to be somewhere on the ocean floor, beneath 15,000 feet of water or more.