Boeing has told the U.S. Federal Aviation Administration (FAA) that a component on the wings of some 737s may not comply with strength and durability requirements.
The FAA said earlier this week that an investigation by Boeing, along with the FAA Certificate Management Office, found that as many as 148 leading edge slat tracks are affected. The slat tracks, manufactured by a Boeing sub-tier supplier, are rail-like devices onto which the leading edge slats are mounted.
The parts may have been installed on as many as 133 Boeing 737NGs and 179 Boeing 737MAXs worldwide, the FAA said.
“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 flight.”
The FAA said it would issue an airworthiness directive that will require operators of the affected airplanes to comply with Boeing’s instructions for identifying and removing the parts.
Boeing 737MAX airplanes have been grounded worldwide in the aftermath of fatal crashes last October in Indonesia and in March in Ethiopia.