[Rhodes22-list] Boeing Stock and Composite Boats

[Ronald Lipton]

Interesting article.  We do some of state-of-the art work
with carbon fiber.  It has great plusses - strength, low 
weight, layup into complex forms.  But when it fails it 
fails badly. 

We are building a set of 
carbon fiber structures using very high stiffness material.  
It has the form of a 90" long x 1" diameter six-sided cylinder.
Our first prototype structure was FedExed from the University 
of Washington packaged inside an ABS plastic cylinder 
surrounded by bubble wrap.  The part arrived with a crack 
at the center line, evidently caused by the bending of the 
outer cylinder during shipment.  

I would certainly worry about layups that may contain voids, 
are not fully inspected, Aluminum is no guarantee either. 
Remember Aloha flight 243
http://www.disastercity.com/flt243/picture.htm

I am still trying to convince my wife that sailing is safer, 
clearly the perferred method.

Ron

----- Original Message ----- 
From: "brad haslett" <flybrad at yahoo.com>
To: <rhodes22-list at rhodes22.org>
Sent: Wednesday, March 30, 2005 9:16 PM
Subject: [Rhodes22-list] Boeing Stock and Composite Boats


> 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
> 
> ---------------------------------------------------
> 
> 
> 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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