Is Boeing's 787 Dreamliner Safe?

Recently the Boeing company announced the first test launch of its newest airplane the Boeing 787 or Boeing Dreamliner which is touted to be one of the most advanced airplanes ever constructed. However, some industry insiders have doubts about the durability of the light weight materials used to construct the airplane. This is because the 787 is first mass produced commercial airplane to use composite material for the majority of its construction.

But what are composites? They're actually composed of multiple layers of material which is laid down and glued to one another such that the overall strength of the material is much greater than that of any layer. Composites have many benefits the greatest of which is their light weight when compared to the traditional aluminum titanium structure of a traditional airplane. This light weight will allow airlines who purchases 787 to save millions of dollars a year in fuel. In addition, the composite construction of the Boeing 787 Dreamliner will allow for the humidity in the cabin to be much higher during flight as composites are more resistant to water than a metal superstructure.

If fuel prices continue to rise, many airlines may choose to invest more heavily in composite airplanes to drive down operational costs. Air Bus, Boeing's european competitor, is also designing a composite commercial airliner which would provide similar fuel efficiency savings.

Besides being lighter than metal, composites are also fairly dent resistant, however this makes detection of damage to the composite material that much more difficult. In fact, new methods of inspection will be required for the Boeing 787 due to its composite construction. Such inspection will require the use of sophisticated laser and or ultrasonic equipment to allow detection of non visible damage to the composite components. However, the inspection of composite planes may require the purchase of millions of dollars of inspection equipment as well as the training of qualified inspectors to do this job.

Obviously, Boeing has a lot riding on the 787 Dreamliner, a new type of airplane which could sink or save the company. Already around 800 orders have been placed for the 787 Dreamliner despite production delays.

Dan Rather, former CBS news anchor, interviewed a former Boeing engineer who was concerned that composites were not fully tested for the Boeing 787. While composites are fairly dent resistant, how the composite is constructed can lead to structural failure. This is because in certain situations, such as those found at the high altitudes where planes cruise, rain and ice can force apart the layers in the composite and lead to a structural failure. This is because water can seep in between the layers of the composite and expand at higher altitudes where it freezes. The daily freeze and thaw cycle compounded over decades of use could, in theory, cause a composite plane to eventually fall apart if not properly inspected and maintained.

While composites can withstand a certain amount of force, at some point the composite will shatter if a significant amount of force is applied, which raises questions about the safety of the airplane in the event of a crash landing. Although the Boeing's 787 Dreamliner is the first commercial airliner to use composite so extensively, many airplanes have been flying with composite parts for years. In fact, some experts believe that structural failure of composite parts may be responsible for several airplane crashes.

On June 1st 2009 Air France Flight 447 crashed into the freezing waters of the Atlantic Ocean resulting in the loss of all passengers and crew, a total of 228 people lost their lives that day. The cause of this accident, the deadliest in the history of the Air France airlines, is still being investigated to this day. The most vital pieces of information which could help solve this mystery are the flight data and voice cockpit recorders contained in the plane's black boxes which lie at the bottom of the ocean and which have not yet been recovered.

The cause of the crash of Air France Flight 447 remains unknown, however, the airplane used in the flight was a newer airplane which incorporated composite material, made of fibers and resins, in its wings and tail section areas. Althought the plane which crashed, an Aerobus A 330, has had an excellent safety record, information about how composites hold up to decades of use has not been collected. Another plane crash, that of Flight 587, was caused in part by the "cracking off" of a tail section of the plane's tail section, and failure of the plane's newer composite fittings were inadequate. Another contributing factor may have been improper use of the tail fin causing it to snap off. However, it is very rare to unheard off for an aluminum tail fin to snap off of a plane.

The plane which was carrying Flight 587 was an Airbus 300-600, and a second Airbus 300-600 was found to have experience in flight problems due to possible delamination of the all-composite tail fin which was not apparent during visual inspection of the plane.

Beyond possible structural deficiencies that composites may develop over long periods of use is the problem that composites don't conduct the electricity of a lighting strike as well as an aluminum fuselage. Every year thousands of commercial airliners are struck by lighting, and usually with little consequence for the plane as the electricity is conducted around the surface of the plane due to its aluminum content, thus protecting the inside of the plane from any serious damage. Circuit breakers may need to be reset by the pilot, but the plane often easily survives the lightning strike. But how will a plane made out of 80% composites by weight survive a lightning strike? Boeing engineers have apparently inserted copper rods into the wings and fuselage of the 787 Dreamliner in the hope that this will be suficient protection for a lightning strike. And extensive flight tests of the Dreamliner 787 are expected to provide a real life test of how the plane holds up to lightning strikes.

Hopefully, passenger safety has been sacrifice to build a more fuel efficient plane and Boeing may need to implement strict inspection and maintenance protocols for their composite planes.

Sources:

http://www.latimes.com/business/la-fi-dreamliner23-2009dec23,0,1717741.story

http://en.wikipedia.org/wiki/Boeing_787

http://gizmodo.com/301291/boeing-dreamliner-could-be-unsafe-dan-rather-reports

http://unsilentgeneration.com/2009/06/13/did-composite-parts-bring-down-air-france-447-new-clues-and-new-safety-issues-for-the-future/

http://en.wikipedia.org/wiki/Air_France_Flight_447

http://www.encyclopedia.com/doc/1P2-487733.html

http://en.wikipedia.org/wiki/American_Airlines_Flight_587

http://www.encyclopedia.com/doc/1G1-83908123.html