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 jam another surface.
It’s rare that a passenger becomes the first to identify a defect that causes major maintenance, though it does 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.
“it des happen” — Gary Leff, 2026.
*chef’s kiss*
This Boeing 737-800, registered as B-1518, was delivered in June of 2015. C-Checks are carried out every 18-24 months (shorter time for short-haul, high frequency aircraft). D-Checks are done every 6-12 years (same thing – 12 years for newer widebodies, 6 years for high-frequency aircraft).
So this plane likely had as many as seven C-Checks and likely one D-Check. Therefore, something like this falls on the airline’s maintenance at his point in an aircraft’s age.
I once had a pax tell me after landing there were holes in the top of the wing, yeah sure.
Went back to look, sure enough 3 moon shaped divots in the wing in the area marked “no step”. A little speed tape and we headed back to base.
Last week on my JetBlue 516 flight from BUF to BOS I was in A14, a coach window seat in an A320. While approaching landing at Logan I noticed that the inside portion of the outer flap was vibrating much more than I had seen one vibrate before. It seemed to move up and down an inch or two. The wind was a bit gusty but it did not affect the landing to any degree. Since we were landing, I had my phone off per instructions so I could not capture it on video. No way to get one of the cabin crew to view it. On my exit I requested to speak to the captain, who was there and willing to listen to me. I told him of my concerns and he promised to report it to maintenance so they could inspect it. I hope it was inspected and I also hope it was in normal condition. See something, say something.
@jns–You wrote, “I had my phone off per instructions so I could not capture it on video. No way to get one of the cabin crew to view it.” Most airlines request that passengers place their cell phones in airplane mode. However, you report that JetBlue requests passengers to turn off their phone cameras while on board. Recording and documenting potentially defective aircraft control equipment, such as wing-flap failures, can be dangerous, especially during takeoff and landing. Asymmetric flaps can cause serious control issues with the aircraft. Passenger videos and photographs are useful for reporting incidents involving potentially defective equipment on the aircraft’s exterior and for helping prevent accidents. Thank you for your update, and fly safe.
@Ken A, I am sorry if I didn’t explain correctly. The crew always asks that all electronics be stowed before landing. I did that. The airplane mode instruction is for flight a while after takeoff and before being stowed for landing as best I know. I didn’t have my digital camera out to capture the view and starting the phone takes too long. The cabin crew were all seated per the captain’s instructions. We were relatively low over water at that time.
I didn’t have any other choice so I watched carefully so I could get an idea of how much up and down the flap was moving. I also compared that part of the outer flap to the farthest part of it and to the part of the inner flap I could see. Those were not moving the same way and the motion of those other ones was very small in comparison. I was not concerned it would snap on my flight but I know that if such movement is not dealt with by proper engineering, fatigue cracking may occur after a while. It may have been within tolerance or it may have been out of tolerance. I just reported what I saw.
The captain was great. Very easy to talk to. He asked enough questions to understand what I saw. He also landed the airplane smoothly.