Boeing 737 panel goes missing mid-air on United Airlines flight to Oregon

The US aviation regulator is investigating the incident on the 25-year-old plane

An airline inspection of the 25-year-old plane revealed that a panel was missing. AP

A United Airlines Boeing 737-800 landed safely in Oregon on Friday after it was found to be missing an external panel, the latest in a series of incidents involving aircraft manufactured by the company.

United Flight 433 left San Francisco at 10.20am. landed at Medford Airport around 1.45pm on Friday carrying 139 passengers and six crew, the Federal Aviation Administration and airline said.

No injuries were reported, according to media reports.

The FAA said a post-landing airline inspection of the 25-year-old plane revealed a missing panel and the agency will investigate, as will United.

“After the aircraft was parked at the gate, it was discovered to be missing an external panel,” a United Airlines representative 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.”

Boeing said that it would defer comment to United about the carrier's fleet and operations.

The airport’s director, Amber 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.

The FAA is investigating the incident. According to the regulator’s records, the plane was built in late 1998.

United Airlines has operated it since November 30, 2011. It is a 737-824, part of the 737-800 series that was a precursor to the Max.

The Rogue Valley Times posted a photo of the plane without the panel. Traffic was briefly halted at the airport to search for the piece.

The panel should have been on the underside of the aircraft where the wing meets the body and next to the landing gear, United said.

In the aftermath of an Alaska Airlines Boeing 737 Max 9 mid-air emergency prompted by a door panel flying off, US aviation incidents are getting more attention.

The door plug was found in the backyard of a high school physics teacher in southwest Portland, along with other debris from the flight scattered nearby.

The Department of Justice has launched a criminal investigation.

Federal regulators are said to have contacted some passengers and crew who were on the January 5 Alaska Airlines flight, The Wall Street Journal first reported.

In a March 6 statement, Boeing said: “Early in the investigation, we provided the National Transport Safety Board with names of Boeing employees, including door specialists, who we believed would have relevant information. We have now provided the full list of individuals on the 737 door team, in response to a recent request.”

Boeing has been under heavy regulatory scrutiny following the January 5 Alaska Airlines incident, with investigations into the company's safety and quality standards in its production process.

The FAA audit of Boeing's 737 Max production process after the Alaska Airlines incident failed 33 of 89 tests, The New York Times recently reported.

A gaping hole where the door panel had been on the Alaska Airlines Boeing 737 Max 9. Reuters

The supplier, Spirit AeroSystems, the maker of fuselage parts for the 737 Max aircraft, passed six of 13 audits and failed the rest, it said.

The 737 is Boeing's most popular aircraft. The Alaska Airlines incident is the latest issue to affect the company’s best-selling jet, which was grounded for two years, in March 2019, after a defect in its flight stabilising system was involved in two fatal crashes.

Last week, a United Airlines-operated Boeing 737 Max rolled onto the grass and off the runway in Houston, prompting investigations.

Also last week, a United-operated Boeing 777-200 bound for Japan lost a tyre after take-off from San Francisco and was diverted to Los Angeles where it landed safely.

A United Boeing 737 on March 4 bound for Florida departing Houston returned to the airport shortly after take-off after the engine ingested some plastic bubble wrap that was on the airfield prior to departure.

Social media posts showed flames coming out of the engine.

On March 6, fumes detected in the cabin of a Boeing 737-800 Alaska Airlines flight destined for Phoenix caused pilots to head back to the Portland airport.

Emirates airline president Tim Clark called for changes this month at Boeing after a series of technical issues in the past couple of months brought the regulatory focus back on the US plane maker.

Dubai's Emirates, the world's biggest long-haul airline and one of Boeing's biggest customers, has also said it will send its own engineers to observe the production process of Boeing's 777 aircraft and Spirit following the latest safety issues.