Will Composite Aircraft Bounce or Shatter

[Thruster87]

Will the new composite fuselage a/c like the 787 BOUNCE or SHATTER when they crash? Boeing engineers are not sure. Cheers

 

 

[Guest ozzie]

Thats a pretty good question. a composite boat hull when thrown up onto rocks will just bounce up and down with the rocks just punching holes in the hull. it takes a fair amount of punishment before they come apart. I watched a 40footer come to grief in the whitsundays. i was standing on the breakwater just 10ft from the boat. it was pounding so hard that the engine punched out of the bottom and the mast tore the deck apart. Sad to watch but interesting to see just how long the hull stayed in relativly one piece.

 

So will the Dreamliner break up on impact like a metal aircraft giving several ways out for the survivors. Or will it stay relatively intact, then catch on fire and those deadly fumes kill everyone who survived the crash. The next big issue is that the rescue teams will have to be fitted out with the correct equipment and how do you get into the aircraft quickly.

 

Some of you may have read the book written on the rescue of solo round the world yachtsman Tony Bullimore (spelling?) While the Navy boat was heading south a boatbuilding company in Brookvale were testing various methods to cut thru a carbon fibre hull, everything from demolition saws and plasma cutters were tried. The only thing i think was a diamond saw that went blunt every few inches. the fumes from the plasma cutter would have killed him before they cut a hole. I recommend this book as great reading btw.

 

So will it bounce or shatter or come apart at the joins of the subassemblies. anyone know how they build these monster parrots?

 

ozzie

 

 

[Vorticity]

I'm interested that the engineers don't know if it will bounce or shatter, what context and form did they say this:;)5: Having seen the results of a composite helicopter that crashed you wouldnt be able to tell which had occured anyway as the entire thing burnt to nothing.

 

 

[Ultralights]

at the usual impact speed of airliners, and their mass, shatter would be the norm. even jabirus will shatter in some instances.

 

 

[Guest ozzie]

The old "probability of survival is proportional to the angle of arrival' rule still applies.

 

 

[geoffreywh]

I made competition model aircraft for years from carbon cloth impregnated with epoxy, when something went quite wrong the wing D boxes would shatter and look like shredded wheat. BUT it depended which type of epoxy was used and the curing method.

 

 

[Guest Fred Bear]

Boeing 787 Dreamliner could be unsafe, report claims

 

And something interesting in the media today:

 

From correspondents in New York

 

Article from: Reuters

 

• 787's fuselage would 'shatter instead of crumple'
   
   
  
• Material may also emit toxic fumes when burning
   
  

 

 

BOEING'S new 787 Dreamliner plane may be unsafe and could lead to more deaths in crashes, according to a US report by journalist Dan Rather to be broadcast today.

 

The plane, which is mostly made from brittle carbon compounds rather than flexible aluminium, is more likely to shatter on impact and may emit poisonous chemicals when ignited, Rather will report.

 

The report is based on interviews with a former Boeing engineer and various industry experts, according to a transcript of the show.

 

"The problem is all the unknowns that are being introduced and then explained away as if there is no problem," former Boeing engineer Vince Weldon told Rather.

 

Mr Weldon described a recent crash in a standard aluminium plane where the dented but intact fuselage kept fire at bay and allowed passengers to leave the plane alive.

 

"With a composite airframe, the fuselage would not crumple, it would shatter... that shattered hole would be there for the fire that's going into the airplane," he said.

 

"Instead of everyone getting out, it would be a far less positive result.''

 

Mr Weldon said he was fired by Boeing after a 46-year career because of his persistent complaints about the design of the 787.

 

He claimed to represent the view of others at Boeing who were afraid to speak out.

 

Boeing, which did not provide officials for on-camera interviews in Rather's report, said Weldon's claims were not valid and the plane would not fly if it was not safe.

 

"We've looked at Mr Weldon's claims. We've had technical committees review them. We do an exceptional amount of testing," said Lori Gunter, a spokeswoman for Boeing's commercial plane unit.

 

"Absolutely, these materials are safe. They are tested, they will be certified."

 

The Federal Aviation Administration (FAA) must find the 787 to be as crashworthy as aluminium planes, and the plane was doing well in those tests so far, she said.

 

Ms Gunter declined to comment on the circumstances of Mr Weldon's departure from Boeing.

 

Boeing's lightweight, fuel-efficient 787 is set for its first test flight between mid-November and mid-December after a three month delay due to a shortage of bolts and problems programming the flight control software.

 

The first 787 is due to be delivered to Japan's All Nippon Airways in May next year, meaning it will have at most six months of flight tests – much shorter than previous jetliner programs.

 

Boeing's rival Airbus, owned by European aerospace company EADS, is also working on a composite fuselage for its new A350 jet, but it is some years behind Boeing in the design and production process.

 

In Rather's report, Mr Weldon and other experts argued that the carbon-composite fuselage would not survive a lightning strike as well as aluminium, would emit toxic fumes when burning, and could easily be damaged without any visible sign.

 

Mr Weldon said Boeing was misrepresenting to airlines the ease of maintenance on carbon fuselage planes.

 

The report cited experts referring to Airbus planes that had carbon parts with problems that were not easily visible.

 

Rather's report also included interviews with aviation experts who saw little or no problem with the 787.

 

"I'm excited to ride on the 787. I'm excited to fly in composite aircraft," said Joseph Rakow, an engineer at consulting company Exponent, in an interview in the report.

 

Todd Wissing, a commercial pilot, said he would fly the 787 as long as the composite materials are rigorously tested.

 

"We put safety as our top priority," he said.

 

"We use the 21st century inspection methods with these new materials. Then we have complete confidence that we can get in that airplane with our passengers and go fly because that's what we can do."

 

Rather was a former CBS News anchor but let the station after a scandal over his reporting on US President George W. Bush's military record.

 

 

[Guest Rocko]

Well, there's no alternative. We all need to contact Boeing and insist they do a proper crash test, for "safety's sake". Just as long as we can all go and see it, bringing our video cameras ;)