I recently read an article by the Boston Globe discussing the recent crash of Air France flight AF 447. This article (by a Globe staff writer, not an aviation professional or an engineer) is attempting to solve a plan crash that happened in 2001, suggesting composite materials may be to blame for that crash, and furthermore, may be to blame for the recent Air France Airbus crash. (Sites no sources)
Composite materials are helping the avaition industry save fuel, and this is directly effecting passengers and the enviroment. Articles such as this delay the general public acceptence of composites at an ever important time. The weight saving advantages of composite materials is slowly finding acceptence in automotive and rail. Some of the worlds brightest engineers design, test, and re-test composite components to an extreme.
Fear helps sell newspapers, and that is exactly what this author was trying to install.
Read for your self: Boston Globe
Photo Credit: oneras
This is an account of a discussion originally posted by George Larson, Editor emeritus of
ReplyDeleteSmithsonian Air & Space Magazine:
"I had recently with a maintenance
professional who salvages airliner airframes for a living. He has
been at it for a while, dba BMI Salvage at Opa Locka Airport in
Florida. In the process of stripping parts, he sees things few others
are able to see. His observations confirm prior assessments of
Airbus structural deficiencies within our flight test and aero
structures communities by those who have seen the closely held reports
of A3XX-series vertical fin failures.
His observations:
"I have scrapped just about every type of transport aircraft from
A-310, A-320, B-747, 727, 737, 707, DC-3, 4, 6, 7, 8, 9, 10, MD-80,
L-188, L1011 and various Martin, Convair and KC-97 aircraft.
Over a hundred of them.
Airbus products are the flimsiest and most poorly designed as far as
airframe structure is concerned by an almost obsession to utilize
composite materials.
I have one A310 vertical fin on the premises from a demonstration I
just performed. It was pathetic to see the composite structure
shatter as it did, something a Boeing product will not do.
The vertical fin along with the composite hinges on rudder and
elevators is the worst example of structural use of composites I have
ever seen and I am not surprised by the current pictures of rescue
crews recovering the complete Vertical fin and rudder assembly at
some distance from the crash site.
The Airbus line has a history of both multiple rudder losses and a
vertical fin and rudder separation from the airframe as was the case
in NY with AA.
As an old non-radar equipped DC4 pilot who flew through many a
thunderstorm in Africa along the equator, I am quite familiar with
their ferocity. It is not difficult to
understand how such a storm might have stressed an aircraft structure
to failure at its weakest point, and especially so in the presence of
instrumentation problems.
I replied with this:
"I'm watching very carefully the orchestration of the inquiry by
French officials and Airbus. I think I can smell a concerted effort to
steer discussion away from structural issues and onto sensors, etc.
Now Air France, at the behest of their pilots' union, is replacing
all the air data sensors on the Airbus fleet, which creates a
distraction and shifts the media's focus away from the real problem.
It's difficult to delve into the structural issue without wading into
the Boeing vs. Airbus swamp, where any observation is instantly
tainted by its origin. Americans noting any Airbus structural issues
(A380 early failure of wing in static test; loss of vertical surfaces
in Canadian fleet prior to AA A300, e.g.) will be attacked by the
other side as partisan, biased, etc. "
His follow-up:
One gets a really unique insight into structural issues when one has
first-hand experience in the dismantling process.
I am an A&P, FEJ and an ATP with 7000 flight hours and I was
absolutely stunned, flabbergasted when I realized that the majority of
internal airframe structural supports on the A 310 which appear to be
aluminum are actually rolled composite material with aluminum rod
ends.
They shattered.
Three years ago we had a storm come through, with gusts up to 60-70
kts., catching several A320s tied down on the line, out in the open.
The A320 elevators and rudder hinges whose actuators had been removed
shattered and the rudder and elevators came off.
Upon closer inspection I realized that not only were the rear spars
composite but so were the hinges. While Boeing also uses composite
material in its airfoil structures, the actual attach fittings for
the elevators, rudder, vertical and horizontal stabilizers are all of
machined aluminum."
Wow, very interesting lllee65... Thanks
ReplyDeleteFrom what I know about certification, all the composite components have been designed and tested to meet the written demands.
The question should not be, are composites strong enough? Rather, are the qualification specs stringent enough?
I am also curious what are "rolled composite material with aluminum rod ends". I am not familiar with "rolled composites"...