Boeing has notified federal regulators that hundreds of 737s are vulnerable to in-flight damage due to faulty wing parts.
Following an investigation conducted by Boeing and the Federal Aviation Administration’s (FAA) Certificate Management Office, the FAA announced on June 2 that 737 MAX and 737 NG airplanes may have been affected by improperly manufactured slat assemblies within the airplanes’ wings and therefore may not meet federal strength and durability requirements.
The FAA identified up to 148 parts manufactured by a Boeing “sub-tier supplier.” The agency said Boeing used serial numbers to identify aircraft on which the suspect parts may have been installed, including 32 NG and 33 MAX aircraft in the U.S. and 133 NG and 179 MAX aircraft in the worldwide fleet.
“The affected parts may be susceptible to premature failure or cracks resulting from the improper manufacturing process,” the FAA said in a statement. “Although a complete failure of a leading-edge slat track would not result in the loss of the aircraft, a risk remains that a failed part could lead to aircraft damage in flight.”
Slat tracks are used to guide the slats on the leading edge of an airplane’s wings, Boeing explained. The company said it has not been informed of any in-service issues related to the parts.
“Boeing is now staging replacement parts at customer bases to help minimize aircraft downtime while the work is completed,” according to a June 2 company statement. “Once the new parts are in hand, the replacement work should take one to two days. Boeing will also issue a safety service bulletin outlining the steps to take during the inspections.”
The FAA said it will issue an Airworthiness Directive mandating Boeing’s service actions to identify and remove the parts and will require airlines with affected aircraft to service the planes within 10 days.
According to FreightWaves’ Air Cargo Market Expert Jesse Cohen, there will be little impact on cargo because most domestic cargo flies on freighters and wide-body aircraft. “Most narrow body aircraft the size of the 737 average only 300 to 400 pounds of non-luggage cargo per departure, which can typically fit on other replacement narrow bodies,” Cohen said. “This is primarily and largely a passenger issue.”
Boeing [NYSE: BA] has seen its stock value drop nearly 20 percent since aviation authorities worldwide began grounding its 737 MAX 8 aircraft in the wake of the Ethiopian Airlines crash on March 10. The FAA is waiting on Boeing to complete changes to the 737 MAX automated flight control systems before it conducts its own final risk assessments and analyses, according to FAA Acting Administrator Dan Elwell in a statement on May 23.
“We’ll also take part in test flights of a modified 737 MAX and weigh all the information together before making the decision to return the aircraft to service,” he said.