Boeing Shares Drop
After Boeing Reported Composite Structural Issues In The 787
By Steve Hall
February 7, 2012 - On Monday Boeing shares fell on the
New York Stock Exchange after the aircraft maker
reported it will need to take corrective action on the
787 Dreamliner carbon-composite fuselage support
The first Boeing launch customer, All Nippon Airways
took delivery of the 787 Dreamliner on September 25,
2011, at Boeing's facilities in Everett, Washington. On
September 27, the Dreamliner flew to Haneda Airport. The
airline took delivery of the second 787 on October 13,
The Boeing 787 contains approximately 35 short tons of
carbon fiber reinforced plastic (CFRP), made with 23
tons of carbon fiber. Carbon fiber composites have a
higher strength-to-weight ratio than traditional
aircraft materials, which helps make the 787 a lighter
are used on fuselage, wings, tail, doors, and interior. Boeing
had built and tested the first commercial aircraft composite
section while studying the proposed Sonic Cruiser nearly five
years before the Bell Boeing V-22 Osprey military transport
which uses 50% composites, and the company's C-17 transport has
over 16,000 lbs of structural composites.
materials are made by combining materials such as carbon fibers
with epoxy, they have been used in airplane components for
decades. Although composites are lighter and stronger than most
metals, their increasing use in commercial airplane structures
such as the fuselage and wings has raised safety concerns (The
GAO Raises Safety Concerns Over The Boeings 787).
fiber, unlike metal, does not visibly show cracks and fatigue,
which has prompted concerns about the safety risks of widespread
use of the material the rival Airbus A350 was later announced to
be using composite panels on a frame, a more traditional
approach, which its contractors regarded as less risky.
In addition, the porous properties of composite materials, which may cause delamination as collected moisture expands with altitude, is a potential issue. Delamination is a mode of failure for composite materials. Modes of failure are also known as 'failure mechanisms'. In laminated materials, repeated cyclic stresses, impact, and so on can cause layers to separate, forming a mica-like structure of separate layers, with significant loss of mechanical toughness.
responded by noting that composites have been used on wings and other
passenger aircraft parts for many years without incident, and that
special defect detection procedures will be instituted for the 787 to
detect any potential hidden damage.
In November 2001,
DOT issued an Emergency Airworthiness Directive as a result of an Airbus
Model A300 B4-605R airplane?s vertical stabilizer which was made from
separated from the
aircraft on take off from John F. Kennedy International Airport. Upon
inspection the rudder was found separated from the vertical stabilizer.
On November 12,
2001, about 9:15 AM, American Airlines flight 587, an Airbus A300-605R,
N14053, crashed into a residential area of Belle Harbor, New York,
shortly after takeoff from John F. Kennedy International Airport, New
York. Flight 587 was a regularly scheduled passenger flight to Las
Americas International Airport, Santo Domingo, Dominican Republic, with
2 flight crewmembers, 7 flight attendants, and 251 passengers aboard the
airplane. The airplane's vertical stabilizer and rudder separated in
flight and were found in Jamaica Bay, New York about 1 mile north of the
main wreckage site.
All 260 people aboard the airplane and 5 people on the ground were killed, and the airplane was destroyed by impact forces and a postcrash fire. Visual meteorological conditions prevailed at the time of the accident.
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