United finds problem in A320 Tail
Not normally a quotable newspaper, USA Today is today reporting UAL found a problem in the composite vertical stab of an A320. Kudos to UAL for going beyond the letter of the A.D. and doing an ultrasound inspection.
Following post will be a piece for last Sundays LA Times on composites.
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United finds defect in tail of one of its Airbus jets
By Marilyn Adams and Alan Levin, USA TODAY
United Airlines has found evidence of a small defect in the tail section of
one of its Airbus jets, officials told USA TODAY.
United and Airbus officials say the defect isn't significant enough to
warrant repair, and the jet is being returned to service. But it's the first
evidence of a flaw in an Airbus jet since a 27-foot tail fin tore lose on
an American Airlines Airbus A300, causing it to crash Nov. 12 in New York,
killing 265 people.
United mechanics found the flaw, a tiny separation in the composite
material, in the area where the vertical tail fin connects to the fuselage.
Airbus officials say this defect does not mean there is a design problem
with its jets.
However, the discovery will be closely examined by crash investigators.
The mechanics found the defect by using an ultrasound test. The discovery is
likely to increase calls for broader ultrasonic testing of composite
material on passenger planes.
The FAA and French authorities ordered visual tests of A300 and A310 jet
tails after the crash, and no damage was found. But a visual test cannot
detect defects within composite material. The United jet, an A320, is a
different model from the one that crashed but has a similarly constructed
tail fin.
United decided to test three Airbus jets with vertical stabilizers that had
been repaired at the factory before delivery. Airbus had detected flaws
inside the composite material on those jets. The American Airlines Airbus
jet that crashed had a similar factory repair.
United's ultrasound test this week on the 6-year-old A320 found a flaw on
the opposite side of the stabilizer from where the factory repair had been
made.
"We found a small ply separation on the other side of the tail," said Lou
Mancini, United's vice president for engineering. "You can't see it - the
indication showed up on an ultrasound test. We think it had been there since
manufacturing."
Mancini said the airline notified the Federal Aviation Administration, and
that United will soon test the other two Airbus jets. The FAA is keeping a
close eye on the issue, said spokeswoman Laura Brown, but so far doesn't
believe there is a safety risk.
Airbus spokesman David Venz said the defect is in an area that doesn't
support the weight of the tail. "We are confident this airplane is fit to
fly," Venz said.
Composites experts Wednesday said it is possible that a minor defect could
exist in the carbon-fiber structure and create no danger. One benefit of
composites is that they tolerate some types of damage better than metals.
A source connected to the crash investigation said ultrasonic tests may be
needed to gauge whether jets have defects. So far, the investigation has not
found evidence that the tail of the A300 that crashed was damaged, but the
examination has barely begun.