December 21, 2005

Crashed Miami seaplane had cracked wing support

By Michael Christie

MIAMI (Reuters) - Federal investigators raised the wreckage
of a twin-engine seaplane from the seabed off Miami Beach on
Wednesday and said they had found "fatigue cracks" that might
have caused the aging aircraft to lose its right wing and
crash, killing at least 19 people.

An aviation expert said cracks were "insidious" in vintage
aircraft like the 58-year-old Grumman G-73T Turbine Mallard,
which plowed into shallow waters near Miami's Art Deco District
on Monday after taking off for the Bahamian island of Bimini.

The aircraft's operator, Chalk's Ocean Airways, voluntarily
grounded its fleet of four remaining aircraft.

Mark Rosenker, acting chairman of the National
Transportation Safety Board, told a news conference the doomed
plane's cockpit voice recorder had been found, after the
fuselage was hauled onto a barge, and the recording device was
sent to Washington for analysis.

However, Rosenker later said the contents of the voice
recorder, a potentially huge clue as to the cause of the crash,
were undecipherable.

"It was treated, it was dried and played late this
afternoon. Unfortunately the recording was unreadable,"
Rosenker told reporters.

The investigation appeared likely to focus on cracks in a
spar connecting the wing to the fuselage. The piece in question
was also sent to Washington to be studied.

"I suspect if they had known that there was a deep or a
serious fatigue crack, and they would have learned that perhaps
through a series of inspections, they would have repaired it
and we wouldn't be here today," Rosenker said.

He added that it would have required "a very serious type
of inspection" to have discovered the fissures. Experts said
fatigue cracks are largely invisible and can only be identified
by soaking components in a chemical dye and then using X-rays.

Chalk's of Ft. Lauderdale voluntarily grounded its
remaining planes, the Federal Aviation Administration said.

Including the plane that crashed, there are 31 registered
G-73s in the United States. Ten have had their original piston
engines replaced by turbo engines and Chalk's operates the only
ones in commercial service, according to the FAA.

Jack London, a Texas attorney who specializes in air safety
cases involving vintage aircraft, said fatigue cracks were
inevitable in old planes with tens of thousands of takeoffs and
landings, and especially in planes retrofitted with more
powerful, modern engines that they may not have originally been
designed for.

London said Chalk's was in a quandary. Spare parts are no
longer manufactured and there are no alternative seaplanes that
can service the route between South Florida and Bimini, a tiny
island with no space for a runway on dry land.

The bodies of 19 of the 20 people on board, including three
infants and two pilots, were recovered, according to the U.S.
Coast Guard. One person remained unaccounted for.

Most of the passengers were residents of Bimini, 50 miles

away, who had come to Miami for Christmas shopping.

(Additional reporting by John Crawley in Washington)