no wonder it looks like fresh paint.

If vibration is causing the screws to loosen, I still think it is surprising that it happened to all two dozen of them at once. But isn't Loctite a simple solution?

I hope that Japan invoices Boeing for tax on that thing at a rate of 220%.

It's not clear from some fuzzy pictures that all screws backed out. Some could have simply had their heads popped off from vibration. It happens to rivets like that.

Whatever the failure mode, it's clearly known by now as the aircraft in question went back into service yesterday.

It's only a matter of time before the details find their way into the public domain.

It appears to me that the panel is NOT part of the fuselage- pressurized section and is strictly/simply a fairing panel. And IMHO as such - a bit of locktite or application of almost any tacky damping material on the inside would suffice to dampen the ' vibration' problems. I find it hard to believe that all fasteners simply vibrated out a the same time.

Using Loctite would make removing the panel somewhat difficult....

From many of the posts, including mx people, this issue appears to be far from rare.

In this case, it landed in an urban environment, and smashed an occupied vehicle window. Could have easily hit a person. It took this long to elevate the issue, but luckily, so far, no loss of life, but certainly the potential is there.
The lazy B's nonchalant attitude to pieces falling off of aircraft for years is a bit concerning.

You really can't achieve reasonable freedom from risk (Safety) by assuming equal "what-ifs" without data to back them up. Breaking a windshield is minor and of course it missed hitting somebody on the head based on the area exposure vs occurrence loss rate

Parts that float to the ground under high windage loads have historically low risk of severe harm. Of course they are not acceptable occurrences and some level of control of the occurrence need be made. However I didn't think that this thread was about the adequacy of the repair incorporation

Not sure it isn't that rare - yes its a known problem with the 777 but given the amount in service and the flying hours that they are racking up, if this type of incident happens once a year then its not that big a deal.

You have to remember that most of the time this problem is caught before it progresses to panel loss - so if the Engineer spots loose screws on a turnround and retorques them it becomes a non-issue. The first panel loss I was involved in we highlighted the issue to Base Maintenance who then started to carry out a specific check on the screws on this panel at minor checks and also made sure that the Line guys were aware of the problem. That was over 10 years ago and the operator hasn't suffered another panel loss.

loma,

The part smashed a window on a vehicle. What would be the result of a human interface? Landing in a highly populated urban area? Couple that with a history of failures with apparently no sucess.

The reality is the number of instances where the panels have come off. It appears that sometime multiples in a single day, at ONE airport. According to mx personnel, this has been a problem for some time.

Liability, coupled with history of failure. Had the panel injured the occupants of the vehicle, either physically or mentally, the investigation would find that this was a known, recuring issue, that Boeing was very well aware of, and decided, for whatever reason, not to remedy, but simply to fix on occurance.
That equals $$$$$$$

No, I think you will find it is the way journalists work.

A thing happens, and the journos look at the 'wires' (24 hour news feeds from companies such as Reuters).

Because the 'thing' is fresh in their minds, they suddenly notice other occurrences of the same thing*, and report those too.

After writing a few stories, they get bored with that subject and move on.

Which is why things often seem to happen in threes, or as an 'outbreak' of similar events.




*which are actually happening all the time.

From the somewhat-fuzzy photo I showed earlier in this thread, it looks as though the head of the top left screw simply pulled through the panel - causing the hole to become enlarged. The next hole over is also enlarged, but not as much - so maybe that was one where the head of the screw was worn off. The other holes are smaller - consistent with screws vibrating loose.

So it would not appear that they all vibrated loose at the same time. What we see is consistent with the problem working its way to the top left of the panel. Then with only two screws left holding the panel, vibration was no longer an issue - one wore/sheered away from motion and the other just tore free.

I'm not saying that this is what happen, but it is a plausible scenario.

There's a link to a clearer version of the photo in my post #14.

I can't see any holes that look like a screw head has pulled through them.

FWIW a close look at two- three holes lower right above curb in photos- blue background- shows ' smoke' like traces typical of metal to metal rubbing- fretting, possibly indicating loose fasteners thru whatever bracket below- especially if bracket is aluminum alloy.

Most of the other fastener holes seem=- repeat seem to have paint in the countersink area ( reflections make it difficult to be sure ). had there been a vibration problem the paint would hav bee rubbed or flaked off exposing the bare material( aluminum or composite under the countersink. The panel may have been recently painted while held in place by only a few fasteners in the corners thus the edges of the panels -- appear-- repeat -- appear -- to have been freeshly painted also.

Just my .00002 cents worth having dealt with fastening issues- sealing issues- on both composites and metals and fatigue tests way too many moons ago

The photo I showed is from the one you linked to. I just rotated it to its upright position and cropped it to view that top edge.

To compare hole sizes, notice how much foliage and brick shows through that top left hole. It looks wide enough to pass the head of a screw - at least given one that had been partially loosened with vibration and allow to bend slightly.

I'd be interested to know how a relatively small light alloy panel could exert enough force on a screw to bend it.

Isn't that panel made of composite (eg fibreglass honeycomb) material?

TOKYO
A panel weighing three kilograms fell from a plane onto a factory near Tokyo, Japanese officials said Thursday, the country's second case in a week after a similar part landed on a car.

No injuries were reported after the panel was discovered inside the factory near Narita Airport in Chiba Prefecture, a spokesman for All Nippon Airways told AFP.

"After consulting with a panel manufacturer, we identified that the panel was one that fell from our plane," a Boeing 767 flying from the southeastern Chinese city of Amoi, said the spokesman, Hiroyuki Miyagawa.

The panel was used as a cover for the emergency slide and ANA said a faulty bottle containing nitrogen gas was to blame.

The nitrogen is used to blow the panel off the plane, allowing the slide to deploy in an emergency but the bottle leaked, the spokesman said, adding it had since been replaced, and apologising.

https://i1.ytimg.com/vi/s8-393NFKww/sddefault.jpg


HPG blows a panel for the slide off the side of the ac, and no one is aware of it? After calling Boeing, Oh hey, look, that was from one of our planes? Walking around the ac, no one notices a piece that big missing with a big yellow cargo slide showing?

That makes 4 panel incidents within the space of a month for aircraft flying out of or to Japan.

It seems to me that this has got to be more than a coincidence. Someone needs to audit the maintenance being conducted in Japan. 4 panels in a month is a public safety threat - Tokyo is EXTREMELY densely populated, it is a miracle that this did not kill somebody.