Boeing 737 MAX operators in the US were 'kept in the dark' about a hardware change linked to the Lion Air crash

  • US aviation groups, including the Federal Aviation Authority, say Boeing didn’t tell them about a device they added to their 737 MAX aricraft which may have contributed to the deadly Lion Air crash.
  • The new device, called an Angle of Attack (AOA) sensor was added to MAX 8 and 9 models to stop it from stalling mid-air.
  • According to the Indonesian National Transportation Safety Committee erroneous AOA sensor readings may have triggered an abrupt dive that brought down the Boeing 737 MAX 8Lion Air Flight JT610 in October.
  • The Lion Air flight JT610 crashed into the Java Sea, off Indonesia, on October 29, killing all 189 people onboard.al

US aviation safety experts and pilots associations say Boeing didn’t tell them about a new flight-control system on 737 MAX aircraft, a sensor which Indonesian officials think could be involved in the deadly Lion Air crash.

Jon Weaks, president of the Southwest Airlines Pilots Association, said they “were kept in the dark” by Boeing,The Seattle Times and Wall Street Journal (WSJ) reported on Monday.

Weaks said: “We do not like the fact that a new system was put on the aircraft and wasn’t disclosed to anyone or put in the manuals.”

The system Weaks says they weren’t told about is an automated stall-prevention system on Boeing 737 MAX 8 and MAX 9 planes.

Lion airhttp://en.wikipedia.org/wiki/File:Boeing_737-900ER_Lion_Air_Spijkers.jpgLion Air.

The system pushes the nose of the aircraft down when a device called the Angle of Attack (AOA) sensor, which is on the outside of the plane, feels the aircraft is facing up too much which could make it stall.

This device can then force the plane downwards to avoid a stall, but to such a degree that pilots can’t pull the aircraft back level.

According to the Indonesian National Transportation Safety Committee erroneous AOA sensor readings may have triggered an abrupt dive that brought down Lion Air Flight JT610 in October.

In a Boeing bulletin about the Lion Air crash, they spoke about the system designed to prevent a plane stalling, and said it could make the plane dive if bad data was provided – they warned pilots about an “erroneous input” from the sensor.

Captain Mike Michaelis, chairman of the safety committee for the Allied Pilots Association representing about 15,000 American Airlines pilots said: “It’s pretty asinine for them to put a system on an aeroplane and not tell the pilots who are operating the aeroplane, especially when it deals with flight controls,” The WSJ reported.

He said: “Why weren’t they trained on it?”


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Heartbreaking photos show shoes belonging to Lion Air crash victims piled up at the recovery site.

A Federal Aviation Authority (FAA) manager familiar with the case also told the WSJ the new AOA sensor wasn’t highlighted in training materials or during meetings between airlines and regulators.

Boeing told airlines in a briefing around a week after the crash that this situation, where the AOA sensor pushed the plane down, could end in a crash, an aviation safety expert with knowledge of the briefing told The Wall Street Journal.

The Lion Air flight JT610 crashed into the Java Sea, off Indonesia, on October 29, killing all 189 people onboard.

Rescue crews have called off the search for evidence and survivors, and have located the black box which stores flight data and may give clues to explaining the crash.

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