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Dreamliner Flaw Escaping FAA No Surprise in
Certification
Failures to spot and anticipate safety flaws during certification of new
aircraft have been linked to 70 percent of U.S. airline-crash deaths in the past
20 years, according to data compiled by Bloomberg.
Boeing Co. (BA)'s
tests concluding the lithium-ion batteries in its 787 Dreamliner couldn't catch
fire are renewing questions about whether complexity of new aircraft can outpace
manufacturers' and regulators' ability to spot shortcomings during design and
certification.
"We don't know what we don't know," Bernard Loeb, who
retired as head of the U.S. National Transportation Safety Board's aviation
division in 2001, said in an interview. "We're still highly dependent on the
knowledge and capability of the human being, and human beings are
fallible."
Improved certification standards have been one reason there
hasn't been a fatal U.S. crash involving a major airline since 2001, NTSB
Chairman Debbie Hersman said in an interview.
"But there are occasions
where those assumptions are incorrect or not conservative enough," she said.
Hersman declined to comment on the current investigation.
In the absence
of regulations for planes and components using new technology, the U.S. Federal
Aviation Administration creates rules known as "special conditions," as it did
in certifying the Dreamliner's batteries in 2007.
That approval, which
the NTSB will examine at a hearing next month, illustrates the need to modernize
standards for approving new aircraft, Kevin Hiatt, president of the Alexandria,
Virginia-based non-profit Flight Safety Foundation, said in an
interview.
Deadliest Crashes
Boeing shares fell 4.3 percent in two
weeks after the Dreamliner was grounded, closing Jan. 29 at $73.65, the low for
this year. They closed March 26 at $86.62, the highest since May 2008 and 17.6
percent above the recent low, before falling 42 cents yesterday.
The rise
included increases of 2.1 percent on March 12, when Boeing's plan to redesign
the batteries was approved by the FAA, and March 15, the day the company said it
expected the 787 back in the air within weeks.
The history of airline
accidents since 1993 is dominated by cases in which manufacturers and aviation
regulators didn't foresee how a plane might fail, according to NTSB accident
findings and its 2006 report on the issue.
Five such U.S. crashes
occurred in that period, according to NTSB findings, including the three most
deadly of the era: USAir Flight 427 on Sept. 8, 1994, killing 132; Trans World
Airlines Inc. (TWAIQ) Flight 800 on July 17, 1996, killing 230; and American
Airlines Inc. (AMR1) Flight 587 on Nov. 12, 2001, killing 265 people.
Out
of 1,123 deaths in the past 20 years on U.S. carriers investigated by the NTSB,
783 occurred in those five accidents, according to data compiled by
Bloomberg.
'Failsafe' Design
Investigators in those cases discovered a
hidden flaw in a hydraulic device that could send a plane plunging out of
control, explosive fuel tanks that were exposed to sparking electrical equipment
during routine operation, and vulnerability to icing in a plane approved to fly
in weather conditions conducive to ice formation.
For almost two years
after the crash near Pittsburgh of a Boeing 737-300 operated by USAir, now a
part of US Airways Group Inc. (LCC), investigators couldn't explain why a
functioning plane dove nose-first into the ground.
Only then did they
discover a hydraulic device that moved the plane's rudder, a vertical panel on
the tail, could swing it in the direction opposite from what pilots intended. In
the accident, the rudder had moved unexpectedly, making the plane
uncontrollable, the NTSB ruled in 1999.
The device was certified in the
1960s as failsafe.
Rigorous Standards
"We've seen it time and time
again," Tom Haueter, who served as NTSB's chief accident investigator before
retiring last year, said in an interview. "Certification has been a big issue in
a number of accidents."
The FAA, which announced a review of the 787's
design on Jan. 11, "takes very seriously" its responsibility for overseeing new
aircraft, the agency said in an e-mailed statement.
"Some have asked the
question whether the FAA has the expertise needed to oversee the Dreamliner's
cutting edge technology," the agency said. "The answer is yes, we have the
ability to establish rigorous safety standards and to make sure that aircraft
meet them."
More recently, the NTSB blamed an April 2, 2011, crash of a
General Dynamics Corp. (GD)'s Gulfstream business jet on miscalculations of
takeoff speeds during certification flights. The crash killed four Gulfstream
employees.
Airbus SAS last year was forced to make repairs that have cost
$319 million (250 million euros) to its latest model, the double-decker A380,
because the wings are prone to cracking, a condition missed during certification
tests.
'Assumptions Kill'
The FAA and aviation authorities in other
nations can't match the engineering resources at companies like Boeing and
Airbus, Haueter said. U.S. regulators must rely on Boeing employees for much of
the certification testing, he said.
Boeing's engineers signed off on most
elements of the Dreamliner battery made by Kyoto-based GS Yuasa Corp (6674).,
leaving final approval to the agency, according to the NTSB. No matter how
honest those engineers are, they're subject to subtle conflicts of interest that
could cloud their judgment, Haueter said.
"It's the assumptions that kill
you," Haueter said. "If things don't work out the way you planned, things can go
very bad, very fast."
Billion Hours
Boeing's tests and analysis of the
787 batteries, outlined March 7 in NTSB preliminary reports, concluded the odds
of a battery catching fire were one in a billion hours of flight, making it
essentially impossible.
The 787's batteries are mostly used for ground
operations, such as starting auxiliary power units and providing brake power
when the plane is in tow.
A Japan Airlines (9201) 787's battery caught
fire Jan. 7 in Boston after the plane had been in commercial service less than
52,000 hours. An internal short-circuit triggered the fire, according to
preliminary findings.
When a battery on an All Nippon (9202)flight in
Japan overheated and smoked Jan. 16, the FAA grounded the plane. Customers of
the 49 Dreamliner in service, including United Continental Holdings Inc., (UAL)
Japan Airlines Co. and All Nippon Airways Co., were forced to juggle schedules
and shift planes.
Boeing, which has a backlog of more than 800
Dreamliners with a list price starting at about $207 million, has halted
deliveries until commercial service resumes.
The FAA gave initial
approval for Boeing's proposed redesign of the battery system March 12, and the
Chicago-based company has said it's confident tests needed to get the plane back
in the air will be completed within weeks.
Improving Safety
So far,
neither the NTSB nor the FAA has said whether the batteries failed the nine
safety conditions imposed on them in 2007.
Among the conditions was an
assurance that the batteries must never have "self-sustaining, uncontrolled
increases in temperature or pressure." The battery in Boston had "thermal
runaway," a condition in which a cell increasingly overheats, and that spread to
other cells, Hersman said Jan. 24.
Boeing's 787 chief project engineer,
Mike Sinnett, said March 14 that damage outside the batteries in both incidents
was limited and "the airplane responded exactly as we had designed and
intended."
Not Perfect
Boeing declined to discuss the battery's
certification because it's part of the NTSB review, spokesman Miles Kotay said
in an e-mail. Certification works well, as evidenced by the lack of airline
accidents in the past decade, he said.
The aircraft industry and the FAA
have learned from earlier accidents, helping each generation of planes to be
safer than the last, said John Cox, a former pilot who participated in the
Pittsburgh accident investigation as a union representative.
In response
to NTSB recommendations and its own internal review of certification, the FAA
made numerous improvements, such as focusing resources in certification on
"safety critical" systems, it said in correspondence with the safety
board.
"When you look at the data, it shows the process is pretty sound,"
Cox said in an interview. "Is it perfect? No."
