Lion Air Crash: Pilots Fought Automatic Safety System Before Plane Plunged

The pilots of Lion Air Flight 610 were engaged in a futile tug-of-war with the plane's automatic systems in the minutes before it plunged into the ocean, killing all 189 people on board.

But investigators say they are at a loss to explain why the pilots didn't follow the same procedure performed by another flight crew the previous day when they encountered a similar issue.
A preliminary report into the crash released Wednesday by Indonesia's National Transportation Safety Committee (NTSC) reveals more details about the final moments of Flight 610, but acknowledges many questions remain.
Data retrieved from the flight recorder shows the pilots repeatedly fought to override an automatic safety system installed in the Boeing 737 MAX 8 plane, which pulled the plane's nose down more than two dozen times.
The system was responding to faulty data, which suggested that the nose was tilted at a higher angle than it was, indicating the plane was at risk of stalling.
According to the report, the pilots first manually corrected an "automatic aircraft nose down" two minutes after takeoff and performed the same procedure again and again before the plane hurtled nose-first into the Java Sea.
CNN aviation analyst David Soucie said that the circumstances created by the plane's automatic correction would have made pilot intervention "impossible."
"The fact that they fought against the MCAS (multiple) times with the trim settings was an impossible scenario to recover from," he said.
Problem previously corrected
A different flight crew had experienced the same issue on a flight from Denpasar to Jakarta the previous day, but had turned off the automatic safety feature, known as the maneuvering characteristics augmentation system (MCAS) and took manual control of the plane.
The feature is new to Boeing's MAX planes and automatically activates to lower the nose to prevent the plane from stalling, based on information sent from its external sensors. Indonesian investigators have already pointed to issues with the plane's angle-of-attack (AoA) sensors, which had proved faulty on earlier flights.
AoA sensors send information to the plane's computers about the angle of the plane's nose relative to the oncoming air to help determine whether the plane is about to stall.
A wallet is seen in the water where the plane went down.
Photos: In photos: Lion Air plane crashes off Indonesia
A wallet is seen in the water where the plane went down.
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A relative of a passenger cries at a hospital in Jakarta.
Photos: In photos: Lion Air plane crashes off Indonesia
A relative of a passenger cries at a hospital in Jakarta.
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President Widodo (front row, second from right) tours the operations center in Jakarta where debris is laid out.
Photos: In photos: Lion Air plane crashes off Indonesia
President Widodo (front row, second from right) tours the operations center in Jakarta where debris is laid out.
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Police work to identify personal belongings that are believed to be from the plane's wreckage.
Photos: In photos: Lion Air plane crashes off Indonesia
Police work to identify personal belongings that are believed to be from the plane's wreckage.
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A police officer studies a map in the search-and-rescue command center.
Photos: In photos: Lion Air plane crashes off Indonesia
A police officer studies a map in the search-and-rescue command center.
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A diver with the Indonesian Navy enters the water off the north coast of Karawang.
Photos: In photos: Lion Air plane crashes off Indonesia
A diver with the Indonesian Navy enters the water off the north coast of Karawang.
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Rescue workers carry a body that was recovered from the waters near Jakarta on October 29.
Photos: In photos: Lion Air plane crashes off Indonesia
Rescue workers carry a body that was recovered from the waters near Jakarta on October 29.
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A woman in Pangkal Pinang prays as she and others wait for news on October 29.
Photos: In photos: Lion Air plane crashes off Indonesia
A woman in Pangkal Pinang prays as she and others wait for news on October 29.
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People gather on the beach as a rescue team prepares to leave the coast of Karawang.
Photos: In photos: Lion Air plane crashes off Indonesia
People gather on the beach as a rescue team prepares to leave the coast of Karawang.
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Wreckage from the plane lies at a port in Jakarta.
Photos: In photos: Lion Air plane crashes off Indonesia
Wreckage from the plane lies at a port in Jakarta.
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Bagus Sunjoyo, head of airport authority for Soekarno-Hatta International Airport, speaks to members of the media during a news conference.
Photos: In photos: Lion Air plane crashes off Indonesia
Bagus Sunjoyo, head of airport authority for Soekarno-Hatta International Airport, speaks to members of the media during a news conference.
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People watch a rescue team as a helicopter flies overhead.
Photos: In photos: Lion Air plane crashes off Indonesia
People watch a rescue team as a helicopter flies overhead.
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People look at the passenger manifest for Lion Air Flight JT 610.
Photos: In photos: Lion Air plane crashes off Indonesia
People look at the passenger manifest for Lion Air Flight JT 610.
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Merdiana Harahap is consoled in Medan, Indonesia. Her husband was on the plane.
Photos: In photos: Lion Air plane crashes off Indonesia
Merdiana Harahap is consoled in Medan, Indonesia. Her husband was on the plane.
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A relative of one of the crash victims tosses flower petals from an Indonesian Navy ship on Tuesday, November 6.
Photos: In photos: Lion Air plane crashes off Indonesia
A relative of one of the crash victims tosses flower petals from an Indonesian Navy ship on Tuesday
Responding to the report, Boeing said it was "deeply saddened" by the loss of the Lion Air flight — but maintained the 737 MAX 8 "is as safe as any airplane that has ever flown the skies," and that the company is "taking every measure to fully understand all aspects of this accident."
Wednesday's preliminary report recommends that Lion Air review its safety culture while the investigation continues, and while officials search for cockpit voice recorder (CVR), which is believed to be buried under mud on the ocean floor.
It should reveal what the pilots were saying and why they didn't turn off the safety feature.
"We need to know what was the pilot discussion during the flight. What was the problem that may heard on the CVR. So why the action difference, this is the thing we need to find. At the moment I don't have the answer," said the NTSC's head of aviation, Capt. Nurcahyo Utomo.