Joint probe by FAA, Boeing reveals some 737 planes may have defective parts

A joint investigation by the US Federal Aviation Investigation (FAA) and Boeing has found that some of the 737 aircraft, including the grounded 737 MAX planes of the world's largest aircraft manufacturer, might have faulty parts on their wings.

Following the revelation, Boeing on Sunday said that it has reached out to airlines that fly 737 planes, and advised them to inspect their slat track assemblies on MAX and Next Generation (NG) aircraft, reported CNN.

The development has come just two weeks after the company acknowledged that it had to correct defects in its 737 MAX flight stimulator, which are used to train pilots. The same model had come under scrutiny following two deadly plane crashes in Indonesia and Ethiopia within six months, which claimed the lives of over 346 people.

The newly discovered issue affects 148 slat tracks produced by a Boeing supplier. The FAA said that a complete failure of a leading edge slat track would not bring down an aircraft, but could damage the plane in flight.

Leading edge slats are an aerodynamic control surface that extends from the front of the wing. They help in providing additional lift to the aircraft.

The development would be a further blow to the efforts of the aircraft maker to get the 737 Max back in the air.

FAA said it has not been notified of any incidents related to the tracks on operating flights, and the fix should take a couple of days to complete.

"We are committed to supporting our customers in every way possible as they identify and replace these potentially non-conforming tracks," said Kevin McAllister, CEO of Boeing Commercial Airplanes, in a statement.