Airbus rudder AD

"Matt Whiting" wrote


True, but we don't have 50 years of experience with composites in
service. Who knows what their deterioration/age related failure modes
may be? Remember, it took a couple of fatal accidents to begin to
understand fatigue and corrosion issues in aluminum...


Matt

My outrage is not whether the composites have a problem, but the method with
which they are to determine if there is a problem.

With some question (there must be a concern, hence an AD) there HAS to be a
better way than a tap test. It does nothing for my confidence.
--
Jim in NC

Morgans wrote:

there HAS to be a better way than a tap test.

Actually, no. Like it or not, but there are situations where the human
eye, ear and feel is still the most accurate method, if carefully done
by a skilled person, of course. (This is just a generic remark. I am no
specialist in composites at all and haven't the slightest clue what
problem airbus might or might not have.)

Stefan

The "tap test", as used on fiberglass homebuilts, is used to detect
voids (air bubbles) in the epoxy/glass matrix. One usually uses a
Quarter to gently tap the surface. If there are any voids, the
difference in sound will be noticeable.

Morgans wrote:
there HAS to be a better way than a tap test.

Stefan wrote:
Actually, no. Like it or not, but there are situations where the human
eye, ear and feel is still the most accurate method, if carefully done
by a skilled person, of course. (This is just a generic remark. I am no
specialist in composites at all and haven't the slightest clue what
problem airbus might or might not have.)

jsmith wrote:

The "tap test", as used on fiberglass homebuilts, is used to detect
voids (air bubbles) in the epoxy/glass matrix. One usually uses a
Quarter to gently tap the surface. If there are any voids, the
difference in sound will be noticeable.

How long do you think it will take to do this on an Airbus rudder?

George Patterson
I prefer Heaven for climate but Hell for company.

George Patterson wrote:

jsmith wrote:

The "tap test", as used on fiberglass homebuilts, is used to detect
voids (air bubbles) in the epoxy/glass matrix. One usually uses a
Quarter to gently tap the surface. If there are any voids, the
difference in sound will be noticeable.


How long do you think it will take to do this on an Airbus rudder?

George Patterson
I prefer Heaven for climate but Hell for company.


Use a Half Dollar then... and pack a lunch..

Dave

The "industrial" version of this is an ultrasonic probe which is passed
over the surface. (Sort of like the OB/GYN's ultrasound device).

jsmith wrote:
The "tap test", as used on fiberglass homebuilts, is used to detect
voids (air bubbles) in the epoxy/glass matrix. One usually uses a
Quarter to gently tap the surface. If there are any voids, the
difference in sound will be noticeable.

George Patterson wrote:
How long do you think it will take to do this on an Airbus rudder?

Morgans wrote:
"Matt Whiting" wrote


True, but we don't have 50 years of experience with composites in
service. Who knows what their deterioration/age related failure modes
may be? Remember, it took a couple of fatal accidents to begin to
understand fatigue and corrosion issues in aluminum...


Matt


My outrage is not whether the composites have a problem, but the method with
which they are to determine if there is a problem.

With some question (there must be a concern, hence an AD) there HAS to be a
better way than a tap test. It does nothing for my confidence.

Sometimes the simple tests really are the best. Visual inspection by
human eyes is still used for a lot of things even though it is well
known to have lots of problems (variability among humans being one of
the biggest).

Matt

"Matt Whiting" wrote in message ...
Sometimes the simple tests really are the best. Visual inspection by human eyes is still used for a lot of things
even though it is well known to have lots of problems (variability among humans being one of the biggest).

Matt

But once someone knows what they are looking for it is very hard to beat...

On Thu, 24 Mar 2005 01:07:28 GMT, "Blueskies"
wrote:


"Matt Whiting" wrote in message ...
Sometimes the simple tests really are the best. Visual inspection by human eyes is still used for a lot of things
even though it is well known to have lots of problems (variability among humans being one of the biggest).

Matt

But once someone knows what they are looking for it is very hard to beat...

Way back in my aerospace days, the guy at the next desk had a casting
he used as an ashtray. (I said this was way back.) The casting had a
tiny crack, and right across the middle of the crack was the QC
inspector's stamp.

Don

"Don Tuite" wrote in message ...
Way back in my aerospace days, the guy at the next desk had a casting
he used as an ashtray. (I said this was way back.) The casting had a
tiny crack, and right across the middle of the crack was the QC
inspector's stamp.

Don

Which begs the question...were they certifying the crack or were they certifying the part?