Boeing has announced that some of its 737 airplanes, including many 737 Max aircraft, may feature faulty parts on their wings.

Working with the US Federal Aviation Administration (FAA), it has contacted 737 operators, advising them to inspect the slat track assemblies on some airplanes.

One batch of slat tracks with particular lot numbers produced by a supplier was found to have a potential non-conformance.

The operators that find the faulty parts can replace them with new ones before returning the airplane to service.

Slat tracks are used to guide the slats located on the edge of an airplane’s wings.

According to Boeing, it has not received any in-service issues associated with this batch of slat tracks.

Boeing is currently replacing components at customer bases to help reduce aircraft downtime while the work is completed.

When the new parts are in hand, the replacement work would be completed in one to two days.

Boeing also added that it will issue a safety service bulletin detailing the steps to take during the inspections.

Boeing has identified 21 737NGs most likely to have faulty parts. For a complete assessment, airlines have been urged to check an additional 112 NGs.

A separate service bulletin will go to 737 MAX operators for carrying out inspections before the MAX fleet returns to service.

“We are committed to supporting our customers in every way possible.”

Boeing identified 20 737 MAX airplanes with faulty parts. Operators will be urged to check an additional 159 MAXs to ensure a complete assessment.

Boeing Commercial Airplanes president and CEO Kevin McAllister said: “We are committed to supporting our customers in every way possible as they identify and replace these potentially non-conforming tracks.”

The FAA will issue an Airworthiness Directive, thereby making Boeing’s recommendations mandatory.