Boeing 737 Max 9 Groundings Remain, More Flights Canceled

Investigators are looking closely at the failure of a mid-cabin door plug that detached during the flight, leading the Federal Aviation Administration to ground all US 737 Max 9 aircraft that have the door plug feature until the aircraft can be thoroughly inspected.

The timeline for a return to service is unclear. The FAA’s Emergency Airworthiness Directive prohibits flight by US airlines or in US territory of all Boeing 737 Max 9 aircraft that have a mid-cabin door plug installed until they pass inspection.

Alaska Airlines acknowledged on Wednesday the Max 9 will not fly for at least several more days and canceled all flights scheduled on that plane through Saturday. The cancellations amount to between 110 and 150 flights per day.

“We hope this action provides guests with a little more certainty, and we are working around the clock to reaccommodate impacted guests on other flights,” the airline said in a statement.

United Airlines said it had canceled 167 Boeing 737 Max 9 flights on Wednesday as it awaits “final approval on the full inspection process. … We expect significant cancellations on Thursday as well.”

The FAA said on Tuesday that Boeing is revising its instructions to operators for inspections and maintenance of the affected 737 Max 9 aircraft.

“Upon receiving the revised version of instructions from Boeing, the FAA will conduct a thorough review,” the FAA said. “The safety of the flying public, not speed, will determine the timeline for returning the Boeing 737-9 Max to service.”

Jennifer Homendy, chair of the National Transportation Safety Board, said Wednesday she thought it would be difficult to verify the planes were fixed and safe to fly without a better understanding of the issue.

The FAA order grounded 171 of the world’s 737 Max 9 aircraft. There are 215 in service.

Some international carriers operate Max 9s that are not affected because they don’t have a mid-cabin door plug. Some other airlines, flying aircraft with the door plugs, have followed the FAA’s lead and grounded their planes.

Mexico’s Aeromexico and Copa Airlines in Panama are among the international carriers with the most 737 Max 9 aircraft in their fleets. Aeromexico said in a statement that it grounded its Max-9s over the weekend in accordance with the FAA’s directive. Copa Airlines said in an updated statement on Wednesday that operations of its 21 Max 9 aircraft remain suspended as the airline awaits further details on inspections.

Turkish Airlines, which has five Max 9 aircraft in its 400-plus plane fleet, said that it will withdraw the aircraft from its fleet “until the technical investigation process is completed and the measures requested by the authorities are implemented.”

While the FAA does not have authority over the operation of aircraft operated by some international carriers, those airlines often follow the agency’s lead.

“The world still looks to the FAA … as the gold standard,” according to Kathleen Bangs, an aviation expert and former commercial airline pilot.

Hundreds of flights have been canceled since Friday on both United Airlines and Alaska Airlines, the two US carriers using 737 Max 9 aircraft.

The airlines have been able to shuffle equipment and accommodate some of those passengers on other aircraft, but the grounding was still affecting operations midweek.

Copa and Aeromexico have also logged numerous cancellations in recent days, according to flight tracking site FlightAware.

Airlines with larger fleets will generally have an easier time shuffling aircraft around to meet customer demand. Location can also play a role. Airports capable of supporting a larger number of aircraft are more likely to have spare planes to replace the grounded ones.

“Under federal law, if an airline cancels or significantly changes your flight – no matter the cause – you’re entitled to a full cash refund if you choose not to travel,” said Scott Keyes, founder of travel site Going, in an email interview with CNN Travel on Tuesday.

“This is true across the board, even if you booked a nonrefundable fare (as most tickets are) and even if you’re in basic economy,” he said.

If you still want to make the trip, “the airline will reaccommodate you on a different flight,” Keyes said. “The simplest way to do this is self-service through the airline’s mobile app (which have gotten quite good in the past year or two), or you can call up the airline and an agent will rebook you free of charge.”