An aerial photo shows Boeing 737 MAX airplanes parked on the tarmac at the Boeing Factory in Renton, Washington, U.S. March 21, 2019.
Lindsey Wasson | Reuters
Boeing has notified the Federal Aviation Administration that parts on the 737 Max and 737 NG may have been improperly manufactured and may not meet regulatory requirements for strength and durability.
The FAA issued a statement on Sunday saying it had conducted an investigation with Boeing which found that up to 148 leading edge slat tracks manufactured by a sub-tier supplier are affected by the problem.
Slats are pieces on the front of the wing and that move to create lift and are important during take-off and landing.
Boeing has identified the serial numbers of the aircraft in which the suspect parts may have been installed.
The agency said 32 NG and 33 Max aircraft are affected in the U.S. Worldwide, 133 NG and 179 Max planes are affected.
“The affected parts may be susceptible to premature failure or cracks resulting from the improper manufacturing process,” the FAA said. “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 fight.”
The FAA said it will issue an airworthiness directive mandating service actions to remove the parts. Aircraft operators have to comply within 10 days. The agency said it has alerted international civil aviation authorities of the issue as well.
The requirement to remove the parts in question on certain 737 NGs within 10 days creates a new wrinkle for carriers during the busy summer travel season. Airlines that operate the 737 Max have canceled thousands of flights through August as the planes remain grounded.
The 737 NG is the model that preceded the 737 Max, which Boeing first delivered to airlines in 2017.
The 737 Max was grounded by the FAA in the wake of a fatal crash in Ethiopia in March, which killed all 157 people on board. The crash in Ethiopia came months after a fatal crash in Indonesia that left 189 people dead.
The aircraft’s anti-stall system is being investigated as a factor in those crashes. Boeing said last month that it has completed a software update for the anti-stall system.
The FAA has given no timeline for when the 737 Max will be certified to fly again.
“The last thing I want is to put a date out there for lifting the grounding,” said Dan Elwell, acting administrator for the FAA.
