Boeing 737 MAX Electrical Problem Affects More Locations on Aircraft
By Alison Sider
The potential electrical problem that prompted airlines to
remove dozens of 737 MAX jets from service last week affects more
areas of the aircraft's flight deck than previously known, Boeing
Co. said Friday.
The aerospace giant said last week that it had told 16 MAX
operators to inspect their jets for a potential electrical problem
that was identified during a plane's assembly in Seattle. The
manufacturing issue, which Boeing now says affects components in a
few locations, will need to be addressed in roughly 90 jets in
airline fleets as well as in many undelivered planes.
Airlines have been eager to put their MAX jets back into service
as they gear up for a busy summer, but carriers have said they have
largely been able to manage without the planes by substituting
other jets. Still, the newly discovered defect threatens to
undermine airlines' and Boeing's efforts to restore passenger
confidence in the aircraft. That challenge comes as the plane maker
is also working to resolve quality issues that have dogged some of
its other commercial and military jets.
The issue disclosed last week involved the electrical grounding
path for the standby power unit in certain electronic systems on
the plane. A change in how that unit was installed during
production in early 2019 could have interrupted that grounding
path; in some circumstances, that could affect how the backup power
source operates, Boeing, the Federal Aviation Administration and
airlines said last week.
The same production changes also impacted the grounding path of
the aircraft's main instrument panel and the rack that houses the
standby power unit, Boeing found during its recent assessments.
Those areas must be inspected and modified as well, Boeing
The issue stems from the use of a paint coating that could
potentially disrupt the grounding pathways, people familiar with
the matter said.
Federal regulators haven't seen the problem as an immediate
safety matter since it impacts a backup system. Carriers including
Southwest Airlines Co. and American Airlines Group Inc. said they
hadn't experienced any operational issues relating to the potential
problem before they grounded the planes last week.
Boeing said it is working with customers on service bulletins
that focus on ensuring a sufficient ground path in the flight deck
of affected jets.
It couldn't be learned when Boeing will formally submit its
proposed fix to regulators. Airlines have said they believe the
solution should be straightforward, and one of the people said it
would likely take around two days per aircraft.
"The FAA will thoroughly review any proposed fix that Boeing
presents to us," the agency said Friday.
Aviation Week reported earlier Friday that grounding issues had
been found in other areas of the affected aircraft. The specifics
of what else is impacted haven't previously been reported.
The MAX re-entered service in December having been grounded
since March 2019 after two accidents killed 346 people. The new
electrical issue isn't related to the automated
flight-control-system malfunction that led to the crashes of planes
flown by Indonesia's Lion Air in October 2018 and Ethiopian
Airlines in March 2019, according to a Boeing spokesperson.
Boeing said it is continuing to assemble new planes and has
delivered around 90 MAX jets since regulators recertified the plane
in November, mostly to U.S. carriers, though some overseas such as
Copa Airlines have been affected. The last delivery was to
Belvia-Belarusian Airlines announced on April 8, a day before
Boeing revealed the inspections.
Write to Alison Sider at email@example.com
(END) Dow Jones Newswires
April 16, 2021 15:11 ET (19:11 GMT)
Copyright (c) 2021 Dow Jones & Company, Inc.