By Alan Levin and Harry Suhartono | Bloomberg News
When the Lion Air crew struggled to control their scuba diving Boeing Co. 737 Max 8, they received help from an unexpected source: an out of service pilot who happened to be in the cockpit.
This extra pilot The child seat in the cockpit properly diagnosed the problem and told the crew how to disable a faulty flight control system and rescue the plane, as two people familiar with the investigation in Indonesia know.
Another crew confronted with identically malfunctioning investigators faced an identical malfunction; the same jetliner crashed into the Java Sea, killing all 189 on board.
The previously unknown detail of the previous Lion Air flight is a new clue to the mystery surrounding the 737 Max pilots who faced the malfunction, who were able to avert disaster while others lost control of their aircraft and crashed are. The presence of a third pilot in the cockpit was not included in the Indonesian National Road Safety Committee's November 28 report on the crash and has not been previously reported.
The so-called skull pilot on the earlier flight from Bali to Jakarta urged the crew to reduce the energy supply to the engine, which pushes his nose down. This is part of a checklist that all pilots need to memorize.
"All the data and information we have on the flight and the plane was submitted to the Indonesian NTSC. Due to the ongoing investigation of the accident, we can not make further comments at this time. Lion Air spokesman Danang Prihantoro said by phone.
The report from the Indonesian Security Committee states that the aircraft had failed several times on previous flights and had not been properly repaired.
Boeing and Indonesian Security Committee officials declined
The security system, which was not supposed to descend and block aircraft too steeply, was critically investigated by the investigators of the crash less than five months later in Ethiopia, where a defective sensor is believed to be the computer […] The Boeing 737 Max was grounded on March 13th by US regulators for similarities with the Lion Air of October 29th.
Boeing's 737 Max was grounded on 13 March by investigators The plane crash of Ethiopian Airlines airline 302 on 10 March crashed
In the wake of the two accidents, questions arose as to how the new 737 model was approved by Boeing. The Inspector General of the Department of Transportation is reviewing the aircraft's registration, and a grand jury under the US Department of Justice is also seeking documentation that may provide for a criminal investigation of aircraft certification.
The FAA had announced last week that this was planned to induce changes in the system to prevent activation when there is no emergency. The agency and Boeing said they will also need additional training and advice in flight manuals.
"We will fully cooperate with the review in the Transport Authority's audit," Boeing spokesman Charles Bickers said in an email. The company declined to comment on the criminal investigation.
Following the crash of Lion Air, two US aviation associations said that the potential risks of the system, referred to as a Maneuver Characteristic Enhancement System (MCAS), had not been adequately described in their manuals or training. The documentation of the Max aircraft contained no explanation, the union leaders said.
"We do not like being notified," said Jon Weaks, president of Southwest Airlines Pilots Assn., In November. "It asks us," Is that all, boys? "I would hope there are no surprises out there."
The Allied Pilots Assn. Union of American Airlines Group Inc. also said that details about the system were not included in the documentation about the aircraft.
Following the crash of Lion Air, the FAA called on Boeing to inform the airlines about the system, and Boeing sent a bulletin to all customers flying with Max reminding them how to disable it in an emergency.
The authorities have released few details on Ethiopian Airlines Flight 302, except that they flew a "very similar" route as the Lion Air aircraft and then dropped sharply into the ground. There were no reports of maintenance problems with the Ethiopian Airlines aircraft before it crashed.
If the same issue has also helped to overthrow Flight 302 from Ethiopian Airlines, this is one of the most annoying issues that crash investigators and air safety consultants concern matters is the reason why pilots on this flight did not carry out the checklist have the system disabled.
"After this dreadful Lion Air accident, you would think that anyone who flies on this plane knows you've turned that off," he told Steve Wallace, the former director of the US Federal Aviation Administration Aircraft accident investigation.
The combination of factors required to crash an aircraft in these circumstances suggests that other problems may have occurred in the crash in Ethiopia, said Jeffrey Guzzetti, who also came to head accident investigations at the FAA and is now a consultant.
"It is simply implausible that this MCAS deficiency can by itself invade a modern jet liner with a trained crew," said Guzzetti.
MCAS is powered by a single sensor near the nose that carries the If the airborne angle was soaring, or if air was traveling parallel to the length of the fuselage or at an angle, the sensor had failed the angle of attack on Lion Air flights and sent false readings indicating that the nose of the aircraft was dangerously upward .