Seaplane that crashed had support beam cracks

MIAMI BEACH, Fla. – A 1940s-era seaplane that lost a wing during takeoff and crashed within sight of the beach, killing all 20 people aboard, had undetected cracks in its airframe that apparently caused the aircraft to break up, federal investigators said Wednesday.

After the discovery was disclosed, Chalk’s Ocean Airways voluntarily grounded its fleet of four planes for inspection. All four planes are the same model as the one that crashed.

The cracks were found in the main support beam of a wing that fell off the seaplane shortly after it took off for the Bahamas on Monday.

As salvage crews and divers worked to haul the wreckage from a channel just off Miami Beach, investigators focused on how the cracks escaped notice by maintenance crews.

Authorities also recovered the plane’s cockpit voice recorder, which was sent along with part of the beam to the National Transportation Safety Board in Washington. The recorder, however, was unreadable for an unknown reason, said Mark Rosenker, acting chairman of the NTSB.

Rosenker said the cracking in the 58-year-old seaplane should have been found and repaired, though the cracks could not be seen with the naked eye, and it would have taken “a very serious” inspection to find them.

If Chalk’s officials had known about the cracking in the Grumman G-73T Turbine Mallards “they would have repaired it and we wouldn’t be here today. I don’t think they knew it,” Rosenker said.

Investigators planned to scour maintenance and flight records for evidence of work done.

The Federal Aviation Administration took no immediate action against the airline.

“These are trying times for this great airline. But we will be back in the air very soon,” Chalk’s general manager, Roger Nair, said in a statement. He did not return phone messages seeking additional comment.

Rosenker said the age of the plane built in 1947 could have been a factor in the cracking. The aircraft was retrofitted in the 1980s with more powerful engines, but it was not clear whether that played any role in the cracking, Rosenker said. Both engines were operating when they hit the water, he added.