Boeing Knew About 737 Max Problems Before Crash But Did Nothing

A Boeing 737 MAX 8 airplane being built for India-based Jet Airways lands following a test flight at Boeing Field in Seattle last month

A Boeing 737 MAX 8 airplane being built for India-based Jet Airways lands following a test flight at Boeing Field in Seattle last month

The warning light, standard on the MAX and included in the pilot manuals, is created to light up if there's a disagreement between the two sensors on either side of the plane's nose that measure the jet's angle of attack - the angle between the oncoming air flow and the airplane's wing.

That left airlines that did not buy the optional indicator - including both Lion Air and Ethiopian Airlines - without the safety feature.

Erroneous data from a sensor responsible for measuring the angle at which the wing slices through the air - known as the Angle of Attack - is suspected of triggering a flawed piece of software that pushed the plane downward in two recent crashes.

In 2017, Boeing discovered an error with the angle of attack (AOA) Disagree alert, which notifies pilots of discrepancies with the sensors that track the lift of a plane's nose.

Boeing briefed the FAA on the display issue in November, after the Lion Air accident, and a special panel deemed it to be " low risk", an FAA spokesman said.

Boeing said it is issuing a display system software update "to implement the AOA Disagree alert as a standard, standalone feature before the MAX returns to service". "That review, which involved multiple company subject matter experts, determined that the absence of the [warning] alert did not adversely impact airplane safety or operation".

The US watchdog, the Federal Aviation Administration, told Reuters Boeing waited 13 months before informing it of the missing alarm in November previous year.

"You better start knowing things about the airplane you're building and selling because my life and the passengers that I carry safely across the globe depend on it", Tajer said.

"We thought [the disagree light] worked", Jon Weaks, the president of the Southwest Airlines Pilots Association, told the Times.

Boeing maintains that the 737 Max was safe to fly even without the alert, which it says provides only "supplemental information".

"Boeing's timely or earlier communication with the operators would have helped to reduce or eliminate possible confusion", the FAA said.

The sensors malfunctioned during an October flight in Indonesia and another in March in Ethiopia, causing software on the planes to push their noses down.

Due to the developments, Boeing has said it will be issuing a display system software update on MAX planes before they are reinstated. The company is working on a software fix it hopes will get the planes flying again this summer, as it faces congressional scrutiny and lawsuits by family members of those who died in the crashes. Those that did not purchase the optional indicator were without the safety feature. Tajer said the American pilots were told in the meeting that on the flight deck of their 737 MAXs, the AOA disagree light would have lit up on the ground and so, because that's a "no-go item", the plane wouldn't even have taken off.

Boeing didn't tell airlines or the FAA about this decision.

The Justice Department is conducting a criminal investigation into whether Boeing misled regulators about features on the plane including flight-control software at the heart of the crash investigations. "All customers with previously delivered MAX airplanes will have the ability to activate the AOA Disagree alert".