CALGARY – Boeing released a response Monday refuting media reports the aviation giant had willfully neglected to activate the disagree alert on 737 MAX aircraft.
It warns pilots of malfunctioning sensors, saying that Boeing indicated in its manual that the disagree lights were functional when in fact they weren’t and connecting it to two fatal aeronautical disasters in recent months.
“…This alert has not been considered a safety feature on aeroplanes and is not necessary for the safe operation of the aeroplane,” the company said.
“Boeing did not intentionally or otherwise deactivate the disagree alert on its MAX aeroplanes.”
The specialized feature which lights up in the cockpit if data about the pitch of the plane’s nose is incorrectly transmitted via the angle of attack (AOA) indicators is not operable unless this system is in use.
However, the highly precise AOA sensors were only an optional feature in MAX aircraft, and for those that opted out, by default did not have the use of disagreeing alerts.
The counterpoint comes close on the heels of Southwest Airlines’ claims that it did not know about the deactivation of the disagree alert until after the crash of the Lion Air flight in Indonesia, and that Boeing erroneously indicated that the disagree lights were functional in its manual.
Boeing is under the microscope for the anti-stall software system or Maneuvering Characteristics Augmentation System, known as MCAS, which was designed to enhance the pitch stability of the aircraft when it’s at an elevated angle of attack.
This makes it resemble previous generations of 737s – but pilots claimed Boeing was not transparent and failed to articulate or provide explicit instructions in it’s manual.
The company is currently working on an update to the software and plans to make the disagree light standard on all new 737 Max jets.
“As the MAX safely returns to the air after the software modifications are approved and certified, all MAX production aircraft will have an activated and operable disagree alert and an optional angle of attack indicator,” the company conceded.
“All customers with previously delivered MAX aeroplanes will have the ability to activate the disagree alert per a service bulletin to airlines.”