Southwest Airlines has grounded two Boeing jets after it discovered structural cracks.
It took the planes out of service and reported the problem to the Federal Aviation Administration and Boeing.
It follows a FAA notice to all airlines about the possibility of cracks developing in Boeing 737 NG planes.
Airlines were told to inspect a part called the ‘pickle fork’ which attaches the fuselage to the wing structure.
The issue was first discovered recently ‘on a small number of airplanes undergoing modifications;’ Boeing said.
It doesn’t affect the Boeing 737 Max which is currently grounded, the FAA said.
The agency told airlines ‘to conduct specific inspections, make any necessary repairs and to report their findings.’
Southwest’s fleet of more than 700 planes is entirely made up of Boeing 737s.
