[Rhodes22-list] Boeing Stock and Composite Boats

[brad haslett]

Somewhere in my 20+ page employment contract it
probably says I can't comment on this stuff on a
public website, so I won't say anything negative. 
I've flown Boeing products and, BOY, do they ever
build an industrial strength jet!  I'm thinking about
buying some of their stock. Aluminum is strong stuff,
and the fiberglass they build radomes out of works
good too. If you'd like to read about how well
composites work in boats, read "The Proving Ground" by
G. Bruce Knecht about the 1998 Hobart Race and how the
Oracle composite boat handled the beating.  Brad

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What made an Airbus rudder snap in mid-air? 

When Flight 961 literally began to fall apart at
35,000 feet, it increased fears of a fatal design flaw
in the world's most popular passenger jet 

David Rose
Sunday March 13, 2005
The Observer 

At 35,000 feet above the Caribbean, Air Transat flight
961 was heading home to Quebec with 270 passengers and
crew. At 3.45 pm last Sunday, the pilot noticed
something very unusual. His Airbus A310's rudder - a
structure 28 feet high - had fallen off and tumbled
into the sea. In the world of aviation, the shock
waves have yet to subside. 

Mercifully, the crew was able to turn the plane
around, and by steering it with their wing and tail
flaps managed to land at their point of departure in
Varadero, Cuba, without loss of life. But as Canadian
investigators try to discover what caused this near
catastrophe, the specialist internet bulletin boards
used by pilots, accident investigators and engineers
are buzzing. 

One former Airbus pilot, who now flies Boeings for a
major US airline, told The Observer : 'This just isn't
supposed to happen. No one I know has ever seen an
airliner's rudder disintegrate like that. It raises
worrying questions about the materials and build of
the aircraft, and about its maintenance and inspection
regime. We have to ask as things stand, would evidence
of this type of deterioration ever be noticed before
an incident like this in the air?' 

He and his colleagues also believe that what happened
may shed new light on a previous disaster. In November
2001, 265 people died when American Airlines flight
587, an Airbus A300 model which is almost identical to
the A310, crashed shortly after take-off from JFK
airport in New York. According to the official report
into the crash, the immediate cause was the loss of
the plane's rudder and tailfin, though this was blamed
on an error by the pilots. 

There have been other non-fatal incidents. One came in
2002 when a FedEx A300 freight pilot complained about
strange 'uncommanded inputs' - rudder movements which
the plane was making without his moving his control
pedals. In FedEx's own test on the rudder on the
ground, engineers claimed its 'acuators' - the
hydraulic system which causes the rudder to move -
tore a large hole around its hinges, in exactly the
spot where the rudders of both flight 961 and flight
587 parted company from the rest of the aircraft. 

Last night Ted Lopatkiewicz, spokesman for the US
National Transportation Safety Board (NTSB), which
conducted the flight 587 investigation, said that the
board was 'closely monitoring' the Canadian inquiry
for its possible bearing on the New York crash. 'We
need to know why the rudder separated from the
aircraft before knowing whether maintenance is an
issue,' he added. 

Airbus - Europe's biggest manufacturing company, to
which British factories contribute major components,
including aircraft wings - has now overtaken Boeing to
command the biggest share of the global airliner
market. In sales literature to operators, it described
the A300 series as a 'regional profit machine'. 

The firm recently launched its superjumbo, the
two-storey A380, which is due in service next year.
Like earlier Airbus models, this relies heavily on
'composite' synthetic materials which are both lighter
- and, in theory, stronger - than aluminium or steel.
Fins, flaps and rudders are made of a similar
composite on the A300 and A310, of which there are
about 800 in service all over the world. 

Composites are made of hundreds of layers of carbon
fibre sheeting stuck together with epoxy resin. Each
layer is only strong along the grain of the fibre.
Aircraft engineers need to work out from which
directions loads will come, then lay the sheets in a
complex, criss-cross pattern. If they get this wrong,
a big or unexpected load might cause a plane part to
fail. 

It is vital there are no kinks or folds as the layers
are laid, and no gaps in their resin coating. Holes
between the layers can rapidly cause extensive
'delamination' and a loss of stiffness and strength. 

Airbus, together with aviation authorities on both
sides of the Atlantic, insists that any deterioration
of a composite part can be detected by external,
visual inspection, a regular feature of Airbus
maintenance programmes, but other experts disagree. 

In an article published after the flight 587 crash,
Professor James Williams of the Massachusetts
Institute of Technology, one of the world's leading
authorities in this field, said that to rely on visual
inspection was 'a lamentably naive policy. It is
analogous to assessing whether a woman has breast
cancer by simply looking at her family portrait.' 

Williams and other scientists have stated that
composite parts in any aircraft should be tested
frequently by methods such as ultrasound, allowing
engineers to 'see' beneath their surface. His research
suggests that repeated journeys to and from the
sub-zero temperatures found at cruising altitude
causes a build-up of condensation inside composites,
and separation of the carbon fibre layers as this
moisture freezes and thaws. According to Williams,
'like a pothole in a roadway in winter, over time
these gaps may grow'. 

Commenting on the vanishing rudder on flight 961, he
pointed out that nothing was said about composite
inspection in the NTSB's report on flight 587. This
was an 'unfortunate calamity', he said. Although the
flight 961 rupture had yet be analysed, he continued
to believe Airbus's maintenance rules were
'inadequate', despite their official endorsement. 

Barbara Crufts, an Airbus spokeswoman, said visual
inspections were 'the normal procedure' and insisted
Williams's case was unproven. 'You quote him as an
expert. But there are more experts within the
manufacturers and the certification authorities who
agree with these procedures.' She disclosed that the
aircraft used in flight 961 - which entered service in
1991 - had been inspected five days before the
incident. She said did not know if the rudder had been
examined. 

Despite these and earlier assurances, some pilots
remain sceptical. The Observer has learnt that after
the 587 disaster, more than 20 American Airlines A300
pilots asked to be transferred to Boeings, although
this meant months of retraining and loss of earnings.
Some of those who contributed to pilots' bulletin
boards last week expressed anger at the European
manufacturer in vehement terms. One wrote that having
attended an Airbus briefing about 587, he had refused
to let any of his family take an A300 or A310 and had
paid extra to take a circuitous route on holiday
purely to avoid them: 'That is how con vinced I am
that there are significant problems associated with
these aircraft.' 

Another seasoned pilot with both military and civilian
experience said: 'Composite experts across the country
advocate state-of-the-art, non-destructive testing to
prevent this type of incident from happening, yet
civil aviation authorities still only require "naked
eye" or other rudimentary inspections. How many more
incidents have to occur for decision-makers to do the
right thing by passengers and crews?' 

He said that while flight 961 had come down safely, to
land a plane without a rudder in a crosswind or
turbulence could be impossible. The rudder was all the
more important on a plane such as an A310, because its
wing design meant that it was 'aerodynamically
unstable' and needed the rudder for stability. 

Air Transat, a charter operator which flies from
Canada to Europe and the Caribbean, said that after
the incident it 'immediately carried out a thorough
visual examination of all its Airbus A310s... and no
anomaly was detected.' 

The separation of the rudder may have further
implications for the cause of the 587 crash. In its
report, the NTSB said the tail and rudder failed
because they were subjected to stresses 'beyond
ultimate load', imposed because the co-pilot, Sten
Molin, overreacted to minor turbulence and made five
violent side-to-side 'rudder reversals'. The report
said the design of the A300 controls was flawed
because it allowed this to happen. 

However, the NTSB investigation has been criticised by
many insiders. Ellen Connors, the NTSB chair, told
reporters last January that the report was delayed
because of 'inap propriate' and 'intense' lobbying by
Airbus over its contents, adding: 'The potential for
contaminating the investigation exists.' In America,
the NTSB staff is small and manufacturers provide many
of the staff employed on air-crash investigations into
their own products. 

Dozens of former accident investigators, engineers and
pilots, including some who were involved in the
official inquiry but were disappointed by its conduct,
poured their expertise into a parallel investigation
run by Victor Trombettas, who lives near the crash
site and runs a website, usread.com. Drawing on the
huge mass of technical data released after the crash,
they question the conclusion that 'aggressive' rudder
inputs were the crash's main cause. 

'I don't think the NTSB did a quality job,' said
Vernon Grose, a Washington safety consultant who is a
former board member. He supported the conclusion of
Trombettas's group - that more than ten seconds before
any rudder movements, the 587 pilots were fighting to
regain control of the aircraft for reasons that remain
unknown: a still-to-be investigated technical failure,
or possibly a terrorist bomb. The crash, he recalled,
took place two months after 9/11. Ninety per cent of
the witnesses who saw the plane from the ground said
they saw smoke or fire billowing from it before the
tail and rudder fell off, Grose said. 

Against this background, a spokeswoman for the
Canadian Transport Safety Bureau, which is performing
the investigation, disclosed that there is 'no
evidence' of any movements by the rudder before its
rupture, while Air Transat confirmed that it had
separated when the plane was at cruising altitude and
speed. 'You barely use the rudder at all in those
conditions,' the former A300 pilot said. 'If this
plane lost a rudder with no one doing anything, it has
to raise new questions about the fate of flight 587.' 

And the pressure is now on the aviation authorities to
review whether testing by the naked eye is really
enough to keep air passengers safe. 






		
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