Racey
09-20-2007, 09:34 AM
http://blog.wired.com/wiredscience/2007/09/dan-rather-make.html
Dan Rather Makes Questionable Case Against Science Behind Boeing Dreamliner
By Aaron Rowe September 19, 2007 | 7:39:52
By taking a cheap shot at Boeing, Dan Rather may be headed for a comeback less graceful than Britney Spears' performance at the MTV Music Awards.
On the most recent edition of his new show, he reported on Tuesday that the new 787 Dreamliner aircraft may be unsafe. Since then, dozens of news agencies have jumped on the bandwagon. Most of them are reporting that the carbon fiber frame may not be as safe as aluminum. Few have bothered to question Rather's claims that the composite materials are brittle, more likely to shatter on impact, and prone to emit poisonous chemicals when ignited.
I haven't yet watched the segment, but I have read the full transcript [doc]. As a researcher trained materials engineering, I consider the written summaries that appeared in the news today to be very misleading.
While there is a lot of weight behind the argument that composite materials are not as well-studied as aircraft aluminum, the reasoning behind the flurry of recent articles may be faulty. First off, if a plane crashes, the composite frame will definitely not be the only source of toxic fumes. Second, high performance composites have been used in fighter aircraft and for years. Sports cars, race cars, and train cars made from composite materials have endured fantastic crashes. Claims that the impact toughness of carbon fiber is inadequate may be premature.
The title of Rather's story, Plastic Planes, indicates a lack of grounding in science. High-performance carbon composites are far stronger than plastics. My main concern is how well they will hold up to water -- a point that is only briefly touched on during the show. Because they are vulnerable to slow and steady degradation by moisture, the new materials may not last as long as aluminum. The report by Rather was correct to explain that testing them for wear and tear will be more difficult. That was, perhaps, his most valid point.
To get a second opinion, I contacted Cirrus Design, a company that has been making small aircraft from composite materials for years. Here is what they had to say:
Though Cirrus' are made with different composite materials than the Dreamliner, there is no reason to believe that composites cannot be made every bit as strong as aluminum. Some would argue there is more energy absorption in composites than in aluminum structures. Also, this Dreamliner must go through FAA Certification before it is allowed on the market, like general aviation aircraft. There is no way the FAA would allow Boeing , nor would Boeing put an unsafe, loaded with people aircraft in the sky. Safety is paramount in decision making with all aircraft manufacturers.
Perhaps this is part of an attempt by Rather to make a comeback after the debacle that resulted in his departure from CBS News. The reporter also recently filed a lawsuit against his former employer for $70 million dollars.
Update: Yesterday, I contacted Tom Hahn, a Professor of Mechanical, Materials, and Aerospace Engineering at UCLA and editor-in-chief of the Journal of Composite Materials. He did not get back to me until late last night. Here is what he had to say:
I have full trust in Boeing's decision to use composites in 787. It is a timely decision based on our understanding of composites stemming from many years of analytical and experimental research.
And he is now Sueing CBS for 70 million dollars
Dan Rather Makes Questionable Case Against Science Behind Boeing Dreamliner
By Aaron Rowe September 19, 2007 | 7:39:52
By taking a cheap shot at Boeing, Dan Rather may be headed for a comeback less graceful than Britney Spears' performance at the MTV Music Awards.
On the most recent edition of his new show, he reported on Tuesday that the new 787 Dreamliner aircraft may be unsafe. Since then, dozens of news agencies have jumped on the bandwagon. Most of them are reporting that the carbon fiber frame may not be as safe as aluminum. Few have bothered to question Rather's claims that the composite materials are brittle, more likely to shatter on impact, and prone to emit poisonous chemicals when ignited.
I haven't yet watched the segment, but I have read the full transcript [doc]. As a researcher trained materials engineering, I consider the written summaries that appeared in the news today to be very misleading.
While there is a lot of weight behind the argument that composite materials are not as well-studied as aircraft aluminum, the reasoning behind the flurry of recent articles may be faulty. First off, if a plane crashes, the composite frame will definitely not be the only source of toxic fumes. Second, high performance composites have been used in fighter aircraft and for years. Sports cars, race cars, and train cars made from composite materials have endured fantastic crashes. Claims that the impact toughness of carbon fiber is inadequate may be premature.
The title of Rather's story, Plastic Planes, indicates a lack of grounding in science. High-performance carbon composites are far stronger than plastics. My main concern is how well they will hold up to water -- a point that is only briefly touched on during the show. Because they are vulnerable to slow and steady degradation by moisture, the new materials may not last as long as aluminum. The report by Rather was correct to explain that testing them for wear and tear will be more difficult. That was, perhaps, his most valid point.
To get a second opinion, I contacted Cirrus Design, a company that has been making small aircraft from composite materials for years. Here is what they had to say:
Though Cirrus' are made with different composite materials than the Dreamliner, there is no reason to believe that composites cannot be made every bit as strong as aluminum. Some would argue there is more energy absorption in composites than in aluminum structures. Also, this Dreamliner must go through FAA Certification before it is allowed on the market, like general aviation aircraft. There is no way the FAA would allow Boeing , nor would Boeing put an unsafe, loaded with people aircraft in the sky. Safety is paramount in decision making with all aircraft manufacturers.
Perhaps this is part of an attempt by Rather to make a comeback after the debacle that resulted in his departure from CBS News. The reporter also recently filed a lawsuit against his former employer for $70 million dollars.
Update: Yesterday, I contacted Tom Hahn, a Professor of Mechanical, Materials, and Aerospace Engineering at UCLA and editor-in-chief of the Journal of Composite Materials. He did not get back to me until late last night. Here is what he had to say:
I have full trust in Boeing's decision to use composites in 787. It is a timely decision based on our understanding of composites stemming from many years of analytical and experimental research.
And he is now Sueing CBS for 70 million dollars