The Federal Aviation Administration late Thursday directed that 120 Boeing 767 aircraft undergo emergency inspections after airline mechanics found damaged bolts in the engine pylons of one of the planes.
Under the directive, airlines must conduct the inspections within five to 10 days. The jetliners were considered to be safe for flight and are not being grounded.
It was unclear Thursday whether the inspections, which take about five hours, would disrupt any flights.
The FAA said seven U.S. airlines, including two cargo carriers, were affected by the order.
The FAA issued the order after damaged bolts were found on the engine mounts of one of the Boeing 767 aircraft, said the agency. No further details, including the identity of the airline, were given.
The U.S. carriers affected by the order are American Airlines, Delta Air Lines, Trans World Airlines, United Airlines, US Airways and UPS and Airborne Express.
The directive applies to 230 Boeing 767s operating worldwide. But the FAA can only require the inspection on U.S. carriers. Other countries normally follow the U.S. lead in such inspection orders.