Boeing plans 787 increase

reply to post by Mikeultra

In my opinion all Airbus products should be grounded, the entire world fleet with their composite Tails until engineers find out why this material failed during flight.

There is no ambiguity here and no reason why you're using this outdated source.

It failed because it was overstressed to the point of catastrophic failure, under conditions the vertical stabiliser was not designed for and not certified for. These conditions occurred because the A300 rudder system does not limit excessive rudder inputs and because the pilot did not react properly to wake turbulence.

The A300 also has had numerous incidents of uncommanded rudder response which some have speculated may have contributed.

Crucially, the accident was not because the vertical stabilizer did not perform as designed, nor because the vertical stabilizer was defective in some way, nor was it because the properties of composites were not known. Therefore assuming the accident aircraft had a metallic vertical stabilizer designed to the same requirements, with the same type of pilot error, and the same interface between pilot and rudder, then it's possible that the exact same kind of incident would have occurred.

Instead of talking about composites, you should really be talking about how the human-machine interface needs to be perfected and that design requirements and regulation regarding large control inputs and structural integrity need to be strengthened.

reply to post by Zaphod58


Surely you're just kidding me now? Have you looked at the high resolution photos that I posted earlier from the Coast Guard? usread.com...
Click on some of those photos and you'll see the real culprit is the spongy composites.

reply to post by Mikeultra


If the rudder had come off, the vertical fin would not necessarily have. However, if the vertical fin failed, then the rudder could, and most likely would separate. You need to learn the difference between the parts before you start yelling conspiracy. The rudder is not attached to the fuselage, only the vertical fin, and only on the front portion of the rudder. So if the rudder separates, it puts limited stress on the vertical fin. If the vertical fin separates however, it takes the rudder with it, and the violence of the separation is going to shear the rudder most likely.

Look at these images carefully, and tell me what you see, still attached.

Air Transat

Not an Airbus or composite, but proves my point

More Air Transat

The vertical fin holds the rudder, not the other way around.

Zaphod58
reply to post by Mikeultra

 

If the rudder had come off, the vertical fin would not necessarily have. However, if the vertical fin failed, then the rudder could, and most likely would separate. You need to learn the difference between the parts before you start yelling conspiracy. The rudder is not attached to the fuselage, only the vertical fin, and only on the front portion of the rudder. So if the rudder separates, it puts limited stress on the vertical fin. If the vertical fin separates however, it takes the rudder with it, and the violence of the separation is going to shear the rudder most likely.

Look at these images carefully, and tell me what you see, still attached.

Air Transat

Not an Airbus or composite, but proves my point[/u

[url=http://www.aero-news.net/images/content/commair/2005/air-transat-airbus-a310-lost-rudder-0305-3a.jpg]More Air Transat

The vertical fin holds the rudder, not the other way around.

edit on 10/26/2013 by Zaphod58 because: (no reason given)

edit on 10/26/2013 by Zaphod58 because: (no reason given)

2 photos have just the vertical fin and the SST has it's rudder but missing a chunk of the vertical fin. How's that?

reply to post by Mikeultra


Exactly. The rudder on Air Transat failed, but the vertical fin didn't. But somehow on 587, the rudder failed and took the vertical fin with it?

The portion of the vertical fin that eventually failed, that led to the crash, btw, was aluminum, not composite. The structure in the tail, including the fuselage attachment points was all aircraft grade aluminum.

reply to post by Mikeultra


I've never heard of a composite made of a carbon fibre shell and honeycomb kevlar core being called "spongy".

reply to post by Zaphod58


So are you saying that AA 587 rudder was composite and the vertical fin was aluminum?

C0bzz
reply to post by Mikeultra

 

I've never heard of a composite made of a carbon fibre shell and honeycomb kevlar core being called "spongy".

You have now, perhaps I should have said spongy looking. I have a little experience with epoxy resins and fiberglass. I repaired a composite canoe crushed by a tree. Not an aircraft, but it is sea-worthy once again.

reply to post by Mikeultra


No. The tail was composite over aluminum. The attachment points where the tail attached to the fuselage were aluminum, as were several other portions of the tail. The NTSB pictures clearly showed aluminum brackets for the tail mount, that were cleanly snapped in two.

Zaphod58
reply to post by Mikeultra

 

Exactly. The rudder on Air Transat failed, but the vertical fin didn't. But somehow on 587, the rudder failed and took the vertical fin with it?

The portion of the vertical fin that eventually failed, that led to the crash, btw, was aluminum, not composite. The structure in the tail, including the fuselage attachment points was all aircraft grade aluminum.

I see your point. But.., I did read another account of this 587 crash that said one of the rudder attachments (lower) broke loose from the vertical fin and that's why it started flapping back and forth breaking the connection to the pilots foot pedals. Then when it kept slamming the fin so much it wrenched it off too.

reply to post by Mikeultra


Wouldn't happen like that. The attachment points could withstand the force of the rudder flopping around like that. The stress had to be on the entire surface of the fin, not just a portion of it.

reply to post by Mikeultra

I flew only twice, once on a DC-10 and once on an Airbus A320. I'm done flying now.

DC-10 has a horrible safety record. By the time it was 5 years old (the 787 is almost 5 years old from first flight) it had already crashed killing 73 people. Its successor the MD-11 has a habit of rolling upside down on fire following a hard landing.


reply to post by luxordelphi




It was clearly merely an aerodynamic fairing that wasn't fitting properly rather than a problem with composites.

Most of the evidence you have used is fabricated and not true. Don't get me wrong there are concerns about composite use, but this panel falling off and AA 587 are not among them.

reply to post by luxordelphi

I'm not sure which statement of mine you're referring to but, yes, I've been accused of this before. Fortunately, in the end, I prevailed and, surprise, surprise, it turned out to be a stranger than fiction solution.

A broken clock is right twice a day.


reply to post by luxordelphi

“Composite materials are more difficult to analyze than simple homogenous metals,” says John Hansman, director of the International Center for Air Transportation, at MIT. “You generally don’t model every fiber in the structure, so you come up with models that have simplifications.”

In electrical and electronic engineering we don't simulate every electron either.

reply to post by Mikeultra


No, the Concorde is missing the top half of its rudder, not its vertical fin. It failed, as I recall, when flying over Australia and it landed in some guys back garden, the rudder, not the plane

waynos
reply to post by Mikeultra

 

No, the Concorde is missing the top half of its rudder, not its vertical fin. It failed, as I recall, when flying over Australia and it landed in some guys back garden, the rudder, not the plane

Oh I thought the U.K. and France had different names for that plane? It was called Concorde by both? From the photo I thought the rudder was just the small lower section. I remember being awestruck watching it approach JFK as it passed over Sandy Hook, N.J. So loud! You then knew roughly what time it was. I think it usually showed up around 6:00 pm eastern.

reply to post by Mikeultra


Concorde like many aircraft had a multi part rudder, where it was in two pieces, an upper and lower.

reply to post by Mikeultra


Yes it was a common name, at first we were leaving the 'e' off the end but ultimately we didn't.

It was certainly an impressive plane, France was lucky we let them help out with it, lol.

reply to post by Zaphod58

Wow, where did I say Boeing set the parameters. Maybe you should read more carefully.

The certification process for this plane is almost pitiable.

Larsen Opening Statement: "Lessons Learned from the Boeing 787 Incidents"

The Boeing 787 pushes the technological envelope. The certification itself was an eight-year process. The 787’s lithium-ion batteries, like many of the aircraft’s design features, are a new and constantly evolving technology not specifically covered by existing FAA regulations.

We know the FAA worked with Boeing to develop Special Conditions that would ensure the safety of this new technology. The process for developing these Special Conditions was collaborative, rigorous and transparent. These conditions took over a year to develop, and were published in the Federal Register for public comment.

Nevertheless, we had two serious safety incidents involving Boeing 787 lithium-ion technology in roughly a week’s time. These incidents caused the FAA and other international regulators to ground the 787 for more than three months.

The grounding raises legitimate questions for the flying public about whether the certification process with the 787 worked as well as it should have.

This sad certification process is not over yet.

Boeing begins first-of-its-kind repair on burned 787

Because the 787 is the first large commercial jet made from carbon-fiber-reinforced plastic composites, there's no precedent for the substantial damage to the Ethiopian jet's hull.

University of Washington professor Mark Tuttle, director of UW's Center of Excellence for Advanced Materials in Transport Aircraft Structures, said proving a bonded repair is sound can be difficult.

"One issue with adhesive bonding is you can inspect the bond with ultrasonic inspection and find no gaps or voids, but nevertheless the strength of the bond is lower than anticipated," he said.

You mentioned that the testing process went "slowly and carefully". I have a question for you: just how slowly and carefully does one need to go when they don't know what they're doing?

(forgot to mention: the first link I put up was a hearing on the certification process for this plane.)

ownbestenemy
reply to post by luxordelphi

 

Interesting is we are talking about the Boeing 787 and you have not gone on a tangent about Airbus and now V-22....how can anyone have a valid discussion regarding this when you keep throwing out irrelevant facts that have no bearing to the discussion of the topic at hand?

Not really a tangent; more like a convergence.

The link I put up on the Osprey has this to say about the Dreamliner:

The Plastic Airframe is Flammable

Last year, one of Boeing's top engineers, Vince Weldon, appeared on "Dan Rather Reports" to proclaim that Boeing's newest aircraft would prove unsafe. This 787 "Dreamliner" passenger jet will have an all composite (i.e. plastic) airframe to save weight. This material has been used successfully in fighter aircraft to reduce weight and improve performance. However, composite material is flammable and produces toxic fumes, but fighter pilots have ejection seats to instantly leave a burning aircraft. Weldon worries that a small fire on a passenger jet could ignite the airframe, and the fire would spread rapidly when fed by air flowing outside at hundreds of miles an hour. He said that sections of a composite aircraft will shatter during a crash landing, killing passengers and allowing outside air to rapidly feed a fire.

And here's the convergence:

The V-22 also has a composite/plastic airframe, rather than the traditional aluminum and fiberglass materials, which are heavier and shatterproof. If Boeing's Weldon thinks composites are too dangerous for commercial passenger aircraft, he must think using them for military assault transport aircraft insane. The Navy Safety Center instructs crash-rescue teams not to attempt to extinguish burning composite aircraft since the smoke is toxic.

reply to post by luxordelphi


Thanks for that article, the word plastic is there! The 787 is indeed plastic. Definitely more flammable than aluminum.

"Behind scaffolding erected more than a week ago at London's Heathrow Airport, where the Ethiopian Airlines plane has been idled since summer, a repair team will glue a giant composite plastic skin patch into the burned crown of the fuselage, said two people with knowledge of the details. Boeing has scheduled five weeks for the repair, one said." www.heraldnet.com...

reply to post by luxordelphi


Boeing has worked with composites for years prior to the 787. The military has used composites in stealth aircraft without any problems for decades.

But suddenly they have no idea what they're doing. It's amazing how that eureka