The FAA on Jan. 6 grounded 171 Boeing 737 MAX 9 planes following the mid-air cabin blowout of a door plug on an eight-week old Alaska Airlines jet. The FAA said the Boeing 737-900ER is not part of the newer MAX fleet but has the same door plug design.

The Boeing 737-900ER has over 11 million hours of operation and 3.9 million flight cycles. The FAA said the door plug has not been an issue with this model.

(Reporting by David Shepardson; Editing by Christian Schmollinger)