"To increase safety, we recommend that operators of the Boeing 737-900ER perform a visual inspection of the door seals in the center of the fuselage to ensure they are securely fastened," the US Federal Aviation Administration (FAA) said in a safety alert published on the evening of January 21.

US officials stressed that the 737-900ER is not part of the 737 MAX family, but the two planes share the same door seal design. The FAA said that some airlines had inspected the door seals on the 737-900ER during maintenance and found “some issues with the fasteners.”

The agency recommended that airlines carry out maintenance procedures involving four screws used to secure the door seal to the fuselage frame “as soon as possible.” A Boeing spokesperson said he “fully supports” the FAA’s move.

Door seals are a quick solution to seal off excess emergency exits on aircraft that have fewer seats than the manufacturer designed. Technically, they are not doors, have no opening mechanism, and do not have emergency slides.

These metal panels, weighing about 27 kg, are fixed to the fuselage with 12 screws and gaskets. In case the airline needs to increase the number of seats and exits on the plane, they can easily be removed and the emergency doors installed.

A series of safety warnings were issued by the FAA after an Alaska Airlines Boeing 737 MAX 9 had a door panel blown off just minutes after takeoff on January 5.

The window in row 26 was blown out, part of the fuselage disappeared, revealing a hole as big as an emergency exit, the pressure inside the cabin dropped sharply, causing many belongings to be sucked out. The pilot then quickly reduced altitude and made an emergency landing, all 177 people on board were safe.

The Boeing 737-900ER is an extended-range version of the 737-900, one of four main variants of the 737 Next Generation family that began operations in 1997. It is the third-generation version of the Boeing 737, one of the world's most popular jetliners.

As of August 2023, Boeing has delivered more than 500 737-900ERs to customers. This aircraft has achieved a total of 11 million operating hours and 3.9 million takeoffs and landings, without any recorded problems with the door seals.

Vu Anh (According to Reuters )