US regulators have threatened to fine Boeing for nearly $4 million for allegedly installing defective slat tracks on 133 of its 737 jets and failing to adequately oversee its suppliers to ensure they complied with quality assurance.
The Federal Aviation Administration (FAA) alleges that Boeing installed ‘weakened’ slat tracks, which are used to guide slats to provide additional lift during take-off and landing.
The FAA further alleges that Boeing knowingly submitted aircraft for final airworthiness certification after determining that the parts could not be used due to a failed strength test.
In an emailed statement, Boeing said it is aware of the proposed fine and that it is “working closely” with customers to take corrective actions.
Boeing has 30 days to respond to the FAA’s letter proposing the penalty, which amounts to $3,916,871.
According to the FAA, some slat tracks fitted by Boeing “were weakened by a condition known as hydrogen embrittlement that occurred during cadmium-titanium plating”.
A spokesperson for Boeing told The National that all affected 737 NGs have been inspected.
They told the newspaper: “We will ensure that all inspections and any necessary part replacements are performed on all 737 MAXs before they return to service.
“We have not been informed of any in-service issues related to the slat tracks themselves.”
The FAA said that the affected slat tracks were supplied by Southwest United Industries (SUI), and alleges that Boeing was informed of the situation.
The FAA further alleges that Boeing certified approximately 48 aircraft potentially equipped with those slat tracks as airworthy.
Boeing knowingly certified an additional 85 potentially affected aircraft as airworthy, the FAA claimed.
Regulators also said that identification of the defective parts was hindered because they were improperly marked.