Another day, another problem for Boeing and United Airlines. On Friday, a post-flight inspection revealed a missing panel on an older Boeing 737-800 that had just arrived at its destination in southern Oregon after flying from San Francisco, officials said, the latest in a series of recent incidents involving aircraft manufactured by the company.

United Flight 433 left San Francisco at 10:20 a.m. and landed at Rogue Valley International-Medford Airport in Medford shortly before noon, according to FlightAware. The airport’s director, Amber Judd, said the plane landed safely without incident and the external panel was discovered missing during a post-flight inspection. No injuries were reported.

The airport paused operations to check the runway and airfield for debris, Judd said, and none was found.

Judd said she believed the United ground crew or pilots doing a routine inspection before the next flight were the ones who noticed the missing panel.

A United Airlines spokesperson said that the flight was carrying 139 passengers and six crew members, and no emergency was declared because there was no indication of the damage during the flight.

“After the aircraft was parked at the gate, it was discovered to be missing an external panel,” the United spokesperson said. “We’ll conduct a thorough examination of the plane and perform all the needed repairs before it returns to service. We’ll also conduct an investigation to better understand how this damage occurred.”

The Federal Aviation Administration also said it would investigate.

The missing panel was on the underside of the aircraft where the wing meets the body and just next to the landing gear, United said.