Planemaker Preparing A Service Bulletin To Address Fatigue
Cracking
As the cancellations of Southwest Airlines flights continues to
mount up, Boeing is reportedly preparing a service bulletin
recommending the inspection of all older-model B737s worldwide,
while the FAA is preparing an emergency AD to address the
problem.
The moves come as cracks have been discovered in the fuselages
of a third Southwest 737. Multiple media sources cite Reuters in
indicating that the planmaker said in a statement Monday that the
directive will apply to the more heavily-used airplanes in
carriers' fleets.
There are more than 900 of the single-aisle aircraft flying with
airlines around the world. A Southwest 737 experienced a
decompression event Friday when a five-foot tear opened up in the
roof of a 737 about 20 minutes after takeoff. The plane landed
safely, and the incident was attributed to cracks in the fuselage
due to a high number of pressurization cycles on the aircraft.
The FAA levied a fine of over $10 million against Southwest in
2008 for not performing mandated inspections for fuselage cracks in
its fleet of 737s. It eventually settled with the agency for a $7.5
million fine along with updated inspection guidelines.
Southwest 737s On The Ramp At Midway. Photo By Robert
Randall
The agency now says it will issue an emergency AD Tuesday
that will require operators of specific early Boeing 737 models to
conduct initial and repetitive electromagnetic inspections for
fatigue damage. This action will initially apply to a total of
approximately 175 aircraft worldwide, 80 of which are
U.S.-registered aircraft. Most of the aircraft in the U.S. are
operated by Southwest Airlines.
"Safety is our number one priority," said Transportation
Secretary Ray LaHood. "Last Friday's incident was very serious and
could result in additional action depending on the outcome of the
investigation."
"The FAA has comprehensive programs in place to protect
commercial aircraft from structural damage as they age," said FAA
Administrator Randy Babbitt. "This action is designed to detect
cracking in a specific part of the aircraft that cannot be spotted
with visual inspection."
The FAA airworthiness directive will require initial inspections
using electromagnetic, or eddy-current, technology in specific
areas of the aircraft fuselage on certain Boeing 737 aircraft in
the -300, -400 and -500 series that have accumulated more than
30,000 flight cycles. It will then require repetitive inspections
at regular intervals.
Last November, the FAA published a rule designed specifically to
address widespread fatigue damage in aging aircraft. The rule
requires aircraft manufacturers to establish a number of flight
cycles or hours a plane can operate and be free from fatigue
damage. The rule requires aircraft manufacturers to incorporate the
limits into their maintenance programs.