In the never-ending saga of the Boeing MAX, a new chapter can be added to its tarnished reputation. As the New York Times reported on January 5, the FAA and Boeing have identified a potential ‘catastrophic’ issue with the wiring in the tailplane.
A rigorous review of the MAX design that is part of the re-certification process of the type highlighted a flaw in the wiring to the motor that drives the horizontal stabilizer. Two bundles seem to be too closely positioned and could cause a short circuit, resulting in the loss of the stabilizer. If the pilots would not recognize the failure in time and respond by manually controlling the stabilizer, this could result in the loss of control and lead to a crash of the aircraft.
NYT reports the wiring issue has been under discussion since December, with Boeing’s new CEO David Calhoun addressing the problem last week during an internal conference call.
In a statement, a Boeing spokesperson has said that “we are working with the FAA to perform the appropriate analysis. It would be premature to speculate as to whether this analysis will lead to any design changes.”
Because that’s what is most likely to happen if the close proximity of the two wiring bundles is deemed too much of a safety problem. If the risk of a short circuit is too high, the FAA has no other option than order Boeing to redesign the wiring bundles. This seems an easy job, but moving the bundles within the tailplane could have an effect on other hardware.
While not comparable as such, remember it has taken Mitsubishi over a year to redesign the wiring and electrical system on the MRJ90/SpaceJet since late 2016 after it discovered a safety issue.
If Boeing needs to do (another) redesign on the MAX, that could be a massive blow to the return to service-schedule which is already under huge pressure. Last week, Ryanair’s Michael O’Leary said he thinks he won’t get his MAX 200 before October. And that was before the NYT reported on the wiring issue.
There is another twist to this story. Not only some 800 MAX are affected, but the wiring issue could also include the 737 Next Generation-family. Which begs the question: if it does, why didn’t the FAA discover the bundling problem when the NG was certified that many years ago? Does this indicate that FAA oversight on Boeing has been lacking for far longer than since the MAX, as we have come to believe for some months?
What’s next in store?
Active as a journalist since 1987, with a background in newspapers, magazines, and a regional news station, Richard has been covering commercial aviation on a freelance basis since late 2016.
Richard is contributing to AirInsight since December 2018. He also writes for Airliner World, Aviation News, Piloot & Vliegtuig, and Luchtvaartnieuws Magazine. Twitter: @rschuur_aero.
This latest New York Times piece says Boeing told the FAA that a wiring short may be an issue. Now, that is exactly the discourse you’d expect in day-to-day operations between operators, manufacturers and regulators. Findings are made, openly shared, and, airworthiness directives and alert service bulletins issued with mandatory compliance time periods. This latest hiccup is the snowball of extensive study of anything remotely linked to MCAS. They’re after complete system integrity.