Accident Claimed 20 Lives

(Editor's Note: The following is the unedited text of the National Transportation Safety Board's latest release concerning the December 19 accident involving a Chalk's Ocean Airways Grumman seaplane. While the probable cause of the accident has yet to be released, it appears increasingly likely fatigue cracks in the aircraft's main spar caused the right wing to separate from the aircraft, sending the plane into the waters of Miami's Government Cut shortly after takeoff.)

The National Transportation Safety Board has released photos depicting fatigue cracks found on the separated wing of the Chalk’s Ocean Airways plane that crashed into the water near Miami Beach on Monday.

On Tuesday afternoon, the right wing of the aircraft was recovered. The wing had separated at the inboard section, at the wing/fuselage juncture. Safety Board engineers and metallurgists agree that the signatures are consistent with fatigue fractures. Portions of the wing are at the NTSB metallurgy laboratory in Washington, DC.

As part of the investigation of this accident, which claimed 20 lives, the Safety Board will extensively examine the wing and other structures in the coming days. The probable cause of this accident has not been determined.

IMAGE 1: Overall view of the inboard end of the right wing as it was recovered from the water. An unlabeled arrow indicates the lower spar cap of the rear spar where fatigue features were observed.

IMAGE 2: Closer view of the fracture surface at the inboard end of the lower spar cap of the right wing rear spar. Unlabeled arrows indicate the location of two offset drilled holes.

IMAGE 3: Closer view of the fatigue region in the horizontal leg of the lower spar cap of the rear spar. Unlabeled brackets indicate fatigue origin areas at the surfaces of the fastener hole, and dashed lines indicate the extent of the fatigue region visible on the fracture surface.

FMI: www.ntsb.gov