Boeing notifies FAA about improperly made parts on 737 Max At least 32 Next Generation and 33 Boeing Max aircraft are affected in the U.S.

Boeing told officials with the Federal Aviation Administration (FAA) that certain parts on its grounded 737 Max passenger planes may have been improperly manufactured, the administration revealed.

The FAA released a statement on Sunday, saying the aircraft maker had expressed concern for as many as 148 parts on the 737 Max and 737 Next Generation, a previous model of the aircraft.

At least 32 Boeing Next Generation aircraft and 33 Boeing Max aircraft could be affected in the U.S., according to the FAA. It said 133 Next Generation and 179 Max aircraft could be affected globally.

One part in particular, the leading edge slat tracks, may have been improperly manufactured and may not meet all applicable regulatory requirements for strength and durability, according to the FAA statement.

"The affected parts may be susceptible to premature failure or cracks resulting from the improper manufacturing process," the statement 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 would issue an Airworthiness Directive to mandate Boeing's service actions to "identify and remove the discrepant parts from service." The FAA said the parts in question were manufactured by a Boeing sub-tier supplier, but it did not provide supplier's name.

Boeing said it contacted all 737 operators and told them to inspect the slat track assemblies on certain airplanes.

"Slat tracks are used to guide the slats located on the leading edge of an airplane’s wings. Boeing has not been informed of any in-service issues related to this batch of slat tracks,” Boeing said in a statement Sunday. “If operators find the parts in question, they are to replace them with new ones before returning the airplane to service."

Kevin McAllister, president and CEO of Boeing Commercial Airplane, said the company would do everything it could to help operators with any potential issues.

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

The 737 Max was grounded worldwide following two deadly crashes involving the model. An Ethiopia Airlines crash in March killed all 157 people on board, marking the second deadly crash of a Boeing 737 MAX 8 plane in just five months.

The FAA issued an emergency order to ground the jets earlier this year, citing satellite-based tracking data that linked the Ethiopia jet's movements to those of Lion Air Flight 610, which killed 189 people when it crashed off Indonesia in October.