The Federal Aviation Administration is ordering a temporary grounding of certain Boeing 737-9 Max jetliners operated by U.S. airlines or in U.S. territory after an Alaska Airlines plane blew out a window Friday night mid-flight.

The FAA is requiring immediate inspections of certain Boeing 737 MAX 9 planes before they can return to flight,” FAA Administrator Mike Whitaker said. “Safety will continue to drive our decision-making as we assist the NTSB’s investigation into Alaska Airlines Flight 1282.”

The agency said it will issue an “Emergency Airworthiness Directive” that will require operators to inspect aircraft before further flight that do not meet the inspection cycles outlined in the EAD. The required inspections will take around four to eight hours per aircraft.

The EAD will affect approximately 171 airplanes worldwide, according to a statement posted on the FAA website.

Alaska Airlines said late Friday night that they would immediately be grounding their fleet of 737 MAX 9 aircraft for inspection.

On Saturday morning, Alaska Airlines issued a statement saying “As of this morning, inspections on more than a quarter of our 737-9 fleet are complete with no concerning findings. Aircraft will return to service as their inspections are completed with our full confidence.”

The jetliner was from traveling from Portland, Oregon, to Ontario, California, when it blew out a window and a portion of its fuselage shortly after takeoff three miles above Portland.

Evan Smith was visiting Portland and was on the flight.

You heard a big loud bang to the left rear," he said. "A whooshing sound and all the oxygen masks deployed instantly and everyone got those on."

According to the flight tracking website FlightRadar24.com, the aircraft reached an altitude of 16,000 feet before turning back to the airport.

“We are emergency, we are depressurized, we do need to return back to, we have 177 passengers. Fuel is eighteen eight," the pilot says after air traffic control granted the plane clearance to a lower altitude.

There was a boy and his mother sitting in that row and his shirt was sucked off him and out of the plane. His mother was holding on to him," Smith said.

Alaska Airlines issued a statement after the incident saying, "Alaska Airlines Flight 1282 from Portland, Oregon to Ontario, California, experienced an incident this evening soon after departure. The aircraft landed safely back at Portland International Airport with 174 guests and 6 crew members. We are investigating what happened and will share more information as it becomes available."