United Airlines Flight 433 landed safely without a plate in Oregon

United Airlines said a missing exterior panel was discovered on board a Boeing plane when it landed at an airport in the US state of Oregon on Friday.

United Flight 433, from San Francisco, arrived at Rogue Valley International Airport in Medford, Oregon, at around 11:30 (18:30 GMT) on Friday, a spokesman said.

The 25-year-old Boeing 737-800 was carrying 139 passengers and 6 crew members.

No one was hurt – the missing painting was not noticed during the flight.

Boeing is under intense scrutiny after a series of high-profile safety incidents.

Amber Good, a senior official at Rouge Valley Medford International Airport, said the plane landed safely and the exterior panel was only discovered missing during a post-flight inspection.

She added: “We will conduct a comprehensive inspection of the plane and make all necessary repairs before it returns to service.”

She added that an investigation would be conducted “to better understand how this damage occurred.”

The missing plate was next to the landing gear, on the underside of the plane, according to photos of the plane posted on social media. All departing and arriving flights at the airport were temporarily halted to search for debris, but none were found.

The US Federal Aviation Authority (FAA) said it was investigating how the panel came apart.

Boeing has come under renewed scrutiny after a January incident involving a Boeing 737 MAX 9 — part of a new family of planes that will replace older 737s — in which an unused cabin door exploded just minutes after takeoff in January.

Testifying before US lawmakers on February 7 after the Alaska Airlines explosion, FAA chief Mike Whitaker said inspections of the 737 Max planes showed that “Boeing’s quality system issues are unacceptable and require further scrutiny.”

Preliminary results of the investigation found that four key bolts intended for an unused door lock in the fuselage appeared to be missing. Whitaker said Boeing would be liable for any future failure or refusal to comply with the FAA.

Earlier this month, fumes were detected in the cabin of an Alaska Airlines Boeing 737-800 bound for Phoenix, forcing the pilots to return to Portland Airport.

At least 50 people were injured Monday after a Boeing 787-9 Dreamliner suddenly plummeted without warning, sending passengers not wearing seatbelts tumbling into the aisles and into the ceiling.

In response to this incident, Boeing told airlines that pilots needed to have their seats checked — after reports said a flight attendant accidentally hit a switch in the cockpit that pushed the pilot's seat forward to the controls — forcing the plane's nose down.

Despite the reported incidents, commercial aviation remains one of the safest ways to travel, experts and regulators say.