United plane from San Francisco to Oregon loses external panel mid-flight, officials say

SAN FRANCISCO -- A United Airlines flight that took off from San Francisco International Airport (SFO) Friday morning landed in Oregon with a missing external panel, according to officials.

United says the missing panel wasn't discovered until the plane landed safely in Medford and that pilots had no idea during the flight that something had happened.

The Boeing 737-800 plane had 139 passengers and six crew members onboard.

United says it will "thoroughly examine the plane and perform repairs and conduct an investigation to know how the damage occurred."

Incidents have plagued the airlines in the past few weeks including several involving planes taking off from SFO.

Most notably United Flight 35 where a tire fell off a Boeing 777 during takeoff and the plane ultimately landed safely at LAX after being diverted.