The US FAA has ordered checks on fuel valves on a wide range of Boeing aircraft to ensure they are safe and replace affected valves that could cause possible fuel tank explosions.
The airworthiness directive is effective April 5 and involves Boeing's 737, 757, 767 and 777 jets.
The FAA estimated that the new directive would affect 2,140 planes in the United States.
The new directive resulted from fuel system reviews conducted by Boeing, the FAA said.
An airworthiness directive is a legally enforceable regulation issued by the FAA to correct an unsafe condition in an aircraft, engine or propeller.