Wiring problem discovered on Boeing 737 MAX

Photo: © Jeff Hitchcock

What is possible to be a another design issue has been discovered on Boeing’s troubled 737 MAX aircraft family.

The Federal Aviation Administration (FAA) of the United States has found that there are potential issues with the wiring looms that control the aircraft’s horizontal stabilizer. It is possible that a short circuit could occur, which would result in an un-commanded movement of the horizontal stabilizer, causing the aircraft to change pitch without the pilot’s input.

It is not yet clear whether this issue could actually pose a risk during the airplane’s operation. If this is found to be a problem, then already build 737 MAX might have to be modified to separate the wiring and therefore avoid potential danger.

This flaw is, however, unrelated to the MCAS (Maneuvering Characteristics Augmentation System) which is being blamed for the two crashes in October 2018 and March 2019.

The aircraft type, which has been grounded worldwide since the second fatal accident, is undergoing intense scrutiny from aviation regulators before it is certified to return to service.

Boeing hopes that the 737 MAX will return to flight at some point in March, and it is unclear at this time if the newly discovered issues will cause any further delays. In December, Boeing announced that it will be halting production of the 737 MAX, as the undelivered backlog of completed aircraft exceeds well over 400 airframes. The final production aircraft will be Line Number #7896, which will roll out in mid-January. It is unknown when production is likely to restart, given the ongoing delays to the type’s return to service.