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Boeing says some of its 737 Max planes may have defective parts
Boeing on Sunday said some of its 737 planes, including many 737 Max aircraft, may have faulty parts on their wings. It's the latest problem Boeing faces as it tries to get its most important and popular airplane, the grounded 737 Max, back in the air. Working with the Federal Aviation Administration, Boeing said it has reached out to airlines that fly 737 planes, advising them to inspect their slat track assemblies on Max and NG aircraft. The 737 NG series includes the 737-600, -700, -800… (www.cnn.com) More...Sort type: [Top] [Newest]
There was a 73X slat track issue in 2007. China Airlines Flight 120, a 738 at ROAH in Okinawa, during slat retraction after landing, something from the slat track penetrated a fuel tank and the fuel ignited. The crew ordered an immediate evacuation so there were no deaths but the hull was a total loss.
It was a bolt that wasn’t secured properly during maintenance and got forced into the fuel tank. Fuel started spilling and once the plane stopped, it came into contact with the hot engine and ignited.
If someone had tried to convince me that neglecting to use one washer could destroy an entire plane, I'd probably have laughed them out of the place. Until now.
Hi Torsten
Thanks for the clarification. I've now looked at the report in more detail. It appears that the 2007 problem was related to the omission of a washer. It seems that the Boeing maintenance procedure permitted or recommended omitting the washer. I don't have time for further research on this but your clarification correctly points out it was not related to the slat track issue under discussion in this thread.
Thanks for the clarification. I've now looked at the report in more detail. It appears that the 2007 problem was related to the omission of a washer. It seems that the Boeing maintenance procedure permitted or recommended omitting the washer. I don't have time for further research on this but your clarification correctly points out it was not related to the slat track issue under discussion in this thread.
The maintenance procedure neither permitted nor recommended omitting the washer, it was done by mistake because the area where the work was being done is hard to reach and see, and the maintenance technician was working by feel alone. The washer slipped off before the nut was attached, and because the bolt head was smaller than the hole in the downstop assembly, it eventually walked out.
Frank, let me save you some time. The nut is smaller than the hole in the downstop assembly, so the washer is the only thing preventing the bolt from falling out. The idea of omitting the washer on purpose is absurd.
Thanks for the explanations everyone. Torsten's and JMartinson's explanations with the "hard to reach" aspect are interesting. I wonder if some special tool is needed. If I was engineering this I would have a captive washer, possibly with locking ridges, on the nut. It can be difficult to retain a washer on bolt while simultaneously trying to get a nut started on the thread, more so in a confined space.
Hard to understand that a bolt securing a slat tract would be designed to be smaller than the hole and a washer used to block part of the hole. ??? Boeing should be made to explain that one.
Boeing got a great deal on bolts.