December 21, 2005

Crashed Miami seaplane had cracked wing spar

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 found a "fatigue crack" that might have
caused the aging aircraft to lose its right wing and crash,
killing at least 19.

An aviation expert said cracks were "insidious" in vintage
aircraft like the 58-year-old Grumman G-73T Turbine Mallard
that 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 planes.

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

The investigation appeared likely to focus on the crack in
a spar connecting the wing to the fuselage. The piece in
question was 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 crack. 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 of those 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.

"Unfortunately you're either going to give up the fleet or
you're going to lose airplanes," London said.

The bodies of 19 of the 20 people on board, including three
infants and two pilots, was 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.

Chalk's has operated between Miami and the Bahamas since
1919, when Prohibition was in full force and the offshore
island chain became a haven for rum-runners.

The airline said it had never suffered an accident
involving passengers before, but one of its aircraft crashed on
takeoff from Key West in 1994, killing both pilots.

(Additional reporting by John Crawley in Washington)