Boeing is telling some airlines flying its 737 model to replace a part on the planes’ wings, a move that could affect more than 100 aircraft.

Boeing said on Sunday that it is working with federal regulators and contacted airlines about potential problems discovered in one batch of “slat tracks” produced by a supplier. The company said it has identified 21 planes most likely to have the parts in question, and it’s advising airlines to check an additional 112 planes. The replacement work should take one to two days after the parts are in hand.

That total does not include the 179 737 Max aircraft that could also have the parts in question. The 737 Max was grounded worldwide following two crashes involving the model.

(AP)