The Federal Aviation Administration said a post-landing airline inspection of the 25-year-old airplane revealed a missing panel.
A United Airlines BA.N 737-800 jet was discovered to be missing an external panel following a flight from San Francisco to Oregon.
The BA.N 737-800 jet landed at Medford Airport at around 1:45pm on Friday local time, carrying 139 passengers and six crew after departing from San Francisco, the The Federal Aviation Administration said.United said it would also investigate and said no emergency was declared because there was no indication of the damage during flight.
Boeing has been under heavy regulatory scrutiny following the January 5 Alaska Airlines incident, with probes into the company's safety and quality standards in its production process.
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