The NTSB yesterday released the probable cause of the Dec. 19, 2005 crash of a Chalk’s Ocean Airways Grumman G-73T Turbo Mallard in Miami. The separation of the Mallard’s right wing shortly after takeoff resulted from “the failure of the Chalk’s Ocean Airways maintenance program to identify and properly repair fatigue cracks in the right wing and the failure of the [FAA] to detect and correct deficiencies in the company’s maintenance program.” During yesterday’s public meeting, NTSB materials group chairman Matt Fox said that a doubler repair on the Mallard’s right wing was ineffective because a row of fasteners was “installed through sealant instead of intact skin, which means the load was not properly transferred between the intact structure and the doublers” and that the repair did not take into account a cracked stringer, “which was the underlying problem for the majority of the skin cracking.” Chalk’s pilots had indicated concern about repeated fuel leaks in the accident airplane. “These repeated fuel leaks are an indication of potential structural problems,” Fox said.