Thousands of passengers face flight cancellations as major airlines saw dozens of Boeing jets grounded after a mid-flight blowout over Oregon.
The US aviation regulator said 171 Boeing 737 Max 9s must be grounded for checks after part of an Alaska Airlines plane’s fuselage fell off on Friday.
Alaska said about 23,000 passengers had flights cancelled on Saturday, with further disruption expected.
United Airlines and Turkish Airlines have also grounded planes.
It follows regular Federal aviation administration ordering “immediate inspections” of 737 Max 9s worldwide.
Required inspections would take around four to eight hours per aircraft, it said.
Boeing said it welcomed the FAA’s decision, adding its teams were in close contact with the regulator.
During Friday’s incident, Alaska Airlines flight 1282 from Portland, Oregon to Ontario, California, reached 16,000ft (4,876m) when it began an emergency descent, according to flight tracking data.
Passengers on board said a large section of the plane’s outer shell fell to the ground shortly after take-off.
Images sent to news outlets show the night sky and lights of portland visible through the gap in the fuselage, with insulation material and other debris also seen.
One passengers said the gap was “as wide as a refrigerator” while another said a child’s shirt was ripped off in the wind as the plane made its emergency landing.
