United, Alaska Airlines report loose hardware on 737 MAX planes

WASHINGTON

United and Alaska Airlines both reported on Jan. 8 that loose hardware had been discovered on some of their Boeing 737 MAX 9 planes during preliminary inspections after a dramatic mid-flight incident last week.

The disclosures come as U.S. federal transportation inspectors probe what caused a so-called door plug component to blow out last week on an Alaska Airlines passenger plane, forcing it to make an emergency landing.

United said on Jan. 8 it had "found instances that appear to relate to installation issues in the door plug, for example, bolts that needed additional tightening."

Hours later, Alaska Airlines said its staff had found that "loose hardware was visible on some aircraft."

National Transportation Safety Board (NTSB) inspectors said late on Jan. 8 that they did not find bolts for the component that came off on the Alaska Airlines flight, but hadn't determined whether they existed or had flown off with the panel.

Through further equipment testing, "we will be able to determine whether the bolts were there," NTSB Chair Jennifer Homendy told reporters.

Homendy didn't comment directly on the latest disclosures from United and Alaska about loose components, saying the probe was focused on Friday's incident. But the board could issue an urgent safety recommendation if need be, she said.

Hundreds of flights have been canceled due to the grounding of a fraction of the MAX fleet.