Boeing Co (NYSE:BA, ETR:BCO) is facing an investigation into another model of its aircraft which uses the same type of door plug that fell off a 737 Max 9 jet mid-flight earlier this month.
A “safety alert” was issued early on Monday by the Federal Aviation Administration (FAA), calling on operators to inspect parts on their Boeing 737-900ER jets.
These use the same door plug designs as those being investigated on the 737 Max 9, with carriers told to make sure parts are properly secured after some reported issues with bolts.
All users should inspect door plug fittings “as soon as possible,” the regulator said, after airlines “noted findings with bolts”.
The news marks another blow for Boeing, which has faced pressure to explain why a door plug - used instead of an exit if jets are running with fewer seats - fell off an Alaska Air flight in early January.
Around 170 737 Max 9 jets were subsequently grounded, largely affecting US-operators Alaska Air and United Airlines.
No UK operators fly the 737 Max 9 configuration with the door plugs, while no 737-900ER models are used domestically either.
“We fully support the FAA and our customers in this action,” a Boeing spokesperson said.