With its 737 MAX fleet currently at around 210 airframes, the carrier has approximately 330 Boeing 737NGs, comprised of the -700, -800, -900 and -900ER models. In fact, as it stands, United is the ...

The FAA's notice applies to certain 737-700, 737-800, 737-900, 737-900ER, 737 Max 8, and 737 Max 9 aircraft. Boeing's website says that 3,461 of those planes have been delivered to US customers.