The FAA's investigation into Boeing is getting wider as it flags another plane model for door-plug inspections

• The FAA told airlines to inspect the door plugs of another Boeing jet, the 737-900ER.
• It uses the same door-plug design as the 737 Max 9 involved in the Alaska Airlines blowout.
• United, Alaska, and Delta Air Lines operate the 737-900ER with a door plug.

A second plane has been dragged into the Boeing 737 Max 9 saga as the Federal Aviation Administration recommended a new set of inspections on Sunday.