Text from WSJ for immediate reading:
Four days went by before officials acted on satellite data showing Malaysia Airlines 3786.KU -2.08% Flight 370 flew for several hours away from the area being covered by a massive international search, people familiar with the matter said—a delay from which investigators are still working to recover.
The satellite's operator, Britain's Inmarsat ISAT.LN -0.35% PLC, on March 11 turned over to a partner company its data analysis and other documents indicating that the plane wasn't anywhere near the areas on either side of Malaysia where more countries and ships had been searching for three days since the plane disappeared. The documents included a map showing two divergent north and south corridors for the plane's route stretching some 3,000 miles from the plane's last previously known location, the people said.
The information was relayed to Malaysian officials by Wednesday, March 12, the people said. Inmarsat also shared the same information with British security and air-safety officials on Wednesday, according to two of the people, who were briefed on the investigation.
Two additional people familiar with the Malaysian side of the probe said the information could have arrived in Kuala Lumpur as late as the morning of March 13.
Malaysia's government, concerned about corroborating the data and dealing with internal disagreements about how much information to release, didn't publicly acknowledge Inmarsat's information until March 15, during a news conference with Prime Minister Najib Razak. Malaysia began to redirect the search effort that day to focus on the areas the information described, and said for the first time that deliberate actions were involved in the plane's disappearance.
The disclosures about how the information made its way into the investigation underline how international efforts to find the plane have been repeatedly marred by distrust among the countries involved, confusion in many of Malaysia's public statements, and criticism from many countries that has led some to suspend or change their search efforts in frustration.
The lost days and wasted resources have threatened to impede the investigation, according to some officials involved with the probe.
The delay also means that 12 days after Flight 370 vanished, investigators are still refining search maps, dividing regions to cover and seeking satellite-surveillance records from several countries along the routes the aircraft is now suspected of taking.
Another government official said Malaysia was cautious about revealing and acting on the data because "we don't want to upset anybody with round after round of confusing information."
U.S. national-security officials haven't commented on information-sharing issues. Britain's Ministry of Defense had no immediate comment and its air-crash investigation agency, which has been invited to assist in the probe, said it couldn't comment on "an ongoing investigation."
China's government has complained about Malaysia's response, with Premier Li Keqiang on Monday urging Mr. Najib to provide "more detailed information in its possession, including third-party information, in a timely, accurate and comprehensive manner," according to China's official Xinhua news agency. China's foreign ministry didn't immediately respond to a request to comment late Wednesday.
Within hours of Flight 370's disappearance on March 8, Inmarsat started searching for clues. What little data it had on the short flight before it disappeared was provided to SITA, a Swiss aviation IT company, on the same day, Inmarsat said.
Late that weekend, Inmarsat's team delved into its databases to retrieve periodic "pings," akin to digital handshakes between the plane, a satellite and a ground station, said an industry official briefed on the investigation. The hourly signals provided a crucial clue that the missing 777 most likely remained intact with its engines presumably running hours after it lost contact with civilian radar.
Inmarsat Senior Vice President Chris McLaughlin said that on Monday, March 10, it began extrapolating the location of the jetliner using the aircraft's changing angle and distance to the satellite, which orbits more than 22,000 miles above a point in the Indian Ocean. Mr. McLaughlin said the data was shared the following day with SITA, which in turn shared it with Malaysian officials.
At that point, the search was still focused primarily in waters east of the Malay Peninsula, and Malaysian officials hadn't confirmed reports that Flight 370 had altered its course to Beijing about an hour after takeoff to fly west across the peninsula. Inmarsat's package showed not only that the plane had continued flying for hours, but that it had made an even more radical course change later, ending up along one of two possible corridors, one heading northwest toward Kazakhstan and the other curving far south over the Indian Ocean.
The Inmarsat package, which included a map of the twin north and south corridors, together with readouts of data from a communication satellite, demonstrated the need for a dramatic shift in search areas, according to people briefed on the investigation.
One person said Malaysia chose not to disclose what it considered raw data, preferring to check it first with international partners.
Mr. Najib, the prime minister, had instructed his officials early on that all information coming in be corroborated with agencies such as the U.S. National Transportation Safety Board and the Federal Aviation Administration before releasing the information publicly, Malaysian officials say. They say that was intended to minimize red herrings in the search.
Complicating matters, Chinese satellite images released last Wednesday showed suspected floating debris from the plane. Though the images turned out to be dead ends, they distracted investigators and delayed announcement of Inmarsat's findings, according to one person close to the situation.
Inmarsat officials, meanwhile, became concerned the data weren't being acted upon quickly enough to help overhaul the search, according to a person familiar with the sequence of events. It turned last Wednesday to U.K. security authorities to more quickly disseminate the data, according to two industry officials. Malaysia Airlines, in turn, instructed SITA to use the U.K. Air Accidents Investigation Branch as the primary conduit for Inmarsat's data, one of these officials said.
Publicly, Malaysian officials gave little new information. Asked last Thursday what data from the aircraft investigators were relying on, Malaysia Airlines CEO Ahmad Jauhari Yahya said "no more systems from the plane" had provided information about the jet's whereabouts.That day, Malaysia's acting transport minister said that "whenever there are new details they must be corroborated."
Throughout this process, the basic theory and underlying data from Inmarsat didn't change significantly, according to three people briefed on the investigation.Rather, the days were spent verifying data and attempting to combine it with estimated fuel consumption to derive more-precise projections of how far the plane could have flown.
"The material was refined, but it wasn't demonstrably different" from what Inmarsat first proposed earlier that week, according to one of these people.
It wasn't clear how U.S. officials obtained the initial Inmarsat data, which they analyzed and helped translate into maps. Regardless, people briefed on the probe agree it took longer than expected for the information to spread from engineers and technical experts who cranked out the first version of the data to policy makers and then back down to officials directing specific elements of the searches.