United Airlines said it’s working with various authorities to determine why most of a fuselage panel on the underside of a Boeing 737-800 tore loose on a short flight from San Francisco to Medford, Oregon, Friday. The damaged panel, which according to a photo obtained by the Rogue Valley Times appears to have been in the gear well area of the 25-year-old plane, was discovered after the plane landed in Medford. It was outside the pressure vessel. United said there was no indication during the flight that anything was wrong so the flight was carried out normally. There were 139 passengers and six crew.
The panel appears to have been held by about two dozen bolts. In the photo, the bolts appear to be in place and it seems like the panel tore loose from the mounts. A small portion remained attached and the ragged edge of that piece suggests the remainder was torn loose. The aircraft has been grounded. “After the aircraft was parked at the gate, it was discovered to be missing an external panel,” United said in a statement. “We’ll conduct a thorough examination of the plane and perform all the needed repairs before it returns to service.”
Reminds me of other incidents of apparent outbreaks of human cancers in a local geographic area. People immediately began “hypothesizing” about various causes, when in reality it was just normal clustering that occurs randomly in events that have large numbers. Here, the “large numbers” are the thousands of daily 737 flights (that number might even be in the hundreds of thousands), so failures of all sorts can be expected. Fortunately, in this instance, the failure was not structural or serious.
Pretty strong clustering around United Airlines too.
Hey Rich, shame on you! We can’t possibly have well thought out data driven math and applied science in commentary here in AvWeb. Haven’t you been keeping up? This area is only for political commentary, conspiracy theories and endless haranguing on nonsensical off topic issues!
Hahahahaha. Love it!
Funny thing about cancer clusters. Sometimes – as you noted – they occur by random chance alone without a common exposure to a cancer causing agent (just as it is unlikely, but does happen on occasion, that ten flips of a fair coin results in ten heads in a row).
But, sometimes cancer clusters are caused by an actual carcinogen, too (see examples in Wikipedia by entering “cancer cluster”). The problem is that without an actual investigation, there is no way to tell the difference between a random event and a causal (and therefore preventable) event.
No epidemiologist would declare a “cancer cluster” to be the result of random chance before actually doing an investigation of possible carcinogen exposure. So, while chance alone is always a possible explanation for the improbable co-occurrence (clustering) of some uncommon event, the presence of an as-yet undiscovered cause is also a possible explanation.
Therein lies the problem. Clusters can be non-causal random events and clusters can be an indication of a causal event. The clustering itself does not provide information about its cause (or lack of one). Careful investigation of clusters sometimes allows for identification of a cause.
maintenance we don’t need no stinking maintenance.
“In a related story, the FAA–in conjunction with news media and “concerned citizens” are planning to call for an investigation of everyone that ever worked on the aircraft–the flight and ground crews that preflighted the aircraft, and whoever was President of Boeing when the aircraft was built 25 years ago.” (sarcasm)
Not sure why the word “older” and the “25-year old plane” appears to be front and center in this story. Regardless of the aircraft’s middle-aged status, a well maintained aircraft will retain all of it’s parts during flight unless of course it wasn’t well maintained.
Probably because the initial reports started off with Boeing as the first word.
This is why pilots do walk-arounds before flight. No doubt a First Officer or maintenance tech saw the damage after landing and set off the alarm. No indication to the crew during flight of the missing piece. I wonder if they are looking for it on the ground? Good luck!
If the fasteners are still in place it suggests that some outside agency caused the loss of the panel. Possibly a bird-strike or damage to the panel during ground handling. Nothing for Boeing to lose sleep over I would expect.
The panel appears to be held in place with camloc quarter turn fasteners. Definitely not bolts. The entire upper edge of the panel remains in place and the rest is gone. Strong possibility that some of the fasteners were not engaged when the airplane departed.
This is simply a quick access panel in a non pressurized area. It is not a panel that carries any significant structural load as camlocs are not designed for that purpose.
Much concern about something that is not structurally critical.
The panel appears to be a composite/honeycoam part.
The suggestion that a bird strike was the cause is absurd.
Human failure in not quarter turning and engaging and ensuring camlock fasteners were indeed secured.
Nothing else……
Well, no need to investigate… The problem has been diagnosed and solved here. 😉
I have some experience with those panels (not at United!). They are 10-32 screws. When the holes in the panels get worn there are large area stainless washers that can be used for reinforcement, don’t see any at the screws that are still there, so my “expert” opinion is that enough holes in the panel got worn that it started vibrating and broke loose.