The US government suggests airlines inspect another type of Boeing 737 aircraft. The Federal Aviation Administration of the United States issued a statement on the 21st, recommending that aviation operators using Boeing 737-900ER aircraft inspect the aircraft's door plugs (embedded emergency doors) to ensure safety. The door design of the Boeing 737-900ER aircraft is similar to that of some models in the Boeing 737 MAX series, both allowing airlines to add cabin seats and install emergency exits. A Boeing spokesperson stated that they fully support the Federal Aviation Administration and customers in taking relevant inspection measures.