Missing exterior panel found after United Airlines plane lands safely in Oregon

(CNN) — A United Airlines flight discovered an exterior panel missing from the plane after it took off from San Francisco, California, and landed in Medford, Oregon, Friday afternoon, the airline said.

United Airlines said in a statement that the plane, carrying 145 passengers and crew, had landed safely and was parked at the gate of Medford Rock Valley International Airport when someone on the ground first noticed the missing panel.

The crew of Flight 433 did not declare an emergency and there was no sign of damage during the flight, the airline said.

According to United, the plane was a Boeing 737-800. It belongs to the older generation, not the new 737 Max aircraft has been in the headlines lately.

United said the missing crew did not affect the plane's flight characteristics.

The missing panel was at the base of the fuselage, under the wing and behind the main landing gear, United spokeswoman Leslie Scott told CNN.

Medford Rogue Valley International Airport Director Amber Judd told the Rogue Valley Times that the plane was not airworthy and “will be here for a while.” Judd added that it was not clear where the missing group was.

“They don't know where they lost it,” Judd told RV Times.

United said it would “thoroughly inspect the aircraft and make any necessary repairs before returning it to service.”

“We will conduct an investigation to better understand how this damage occurred,” the airline added.

The Central Aviation Authority has said that an investigation will be conducted into the incident.

Operations at the Oregon airport were suspended while a runway safety inspection was conducted after the plane landed safely around noon, Judd told CNN in a statement. “After finding that there was no debris at the airport, normal operations at the MFR resumed after a few minutes,” Judd added.

The discovery of the missing crew comes as United faces a series of incidents involving multiple flights, including an engine that consumed a bubble mid-flight and a mid-flight fire and another plane that lost a tire after takeoff.