Passenger Spots Loose Wing Part On Boeing 737 — Forcing Airline To Pull Jet From Service

A passenger on China’s Shenzhen Airlines flight 9804 from Wuxi to Shenzhen flagged a concerning mechanical problem on their Boeing 737-800 on Wednesday May 13. They noticed something wrong with the wing, showed a photo to cabin crew, and a flight attendant brought the photo to the cockpit. There was apparently a flap rail fairing detached from the right wing.

The flight landed in Shenzhen and the aircraft, registered B-1518, was taken out of service for maintenance. Chinese social media reports that the airline later called the passenger around 10 p.m. that night to say the equipment did indeed have a problem. That’s the part of the story I find implausible.

中国一名乘客上飞机前拍摄机翼异常，向机组人员汇报，最终此次航班飞行真的被取消了。

乘客发现异常：5月13日，在深圳航空 ZH9804 航班（无锡飞深圳）上，乘客拍摄到飞机外部结构（疑似襟翼或缝翼）存在异常。… pic.twitter.com/uoPW3pqNmF

— 小牛 (@Xiaoniu6161) May 17, 2026

The same plane later operated Shenzhen – Chengdu and additional flights afterward, so social media claims that this was the plane’s “last flight” are not quite accurate – it was the last flight until maintenance was performed on the aircraft.

On a Boeing 737, a flap rail fairing are canoe-like under the wing cover flap mechanism. They clean up airflow. My reading suggests that one or two of these can actually be missing here with performance penalties of 150 pounds for takeoff and landing and 300 pounds for enroute climb. A plane can be dispatched under this condition (if properly identified, inspected and logged). However, a partially detached fairing is somewhat more concerning than a missing one since it could jame another surface.

It’s rare that a passenger becomes the first to identify a defect that causes major maintenance, though it des happen. Passengers have a view of wings, engines, and other parts of the aircraft that pilots don’t see from the cockpit and not every issue generates a warning indicator, especially if the issue is not with a flight control system.

However, I’ve written about a United flight where passengers reported wing slat damage, a pilot inspected from the cabin, and then diverted the flight, and also about a Delta flight where a passenger took video of a dislodged flap.