The National Transportation Safety Board has recommended that the Federal Aviation Administration verify the maintenance programs of commercial aircraft operators, establishing stringent criteria for spotting recurring or systemic discrepancies, to include a comprehensive engineering evaluation. The recommendations stem from the Dec. 19, 2005 crash shortly after takeoff of a Grumman G-73T Turbo Mallard (N2969) amphibious aircraft operated by Chalk’s Ocean Airways near Miami, FL. Safety Board investigators found numerous fuel system maintenance issues in probing the accident that took 20 lives. The aircraft’s right wing separated during flight because of the company’s failure to properly repair fatigue cracks in the wing. The NTSB said continued fuel leaks indicated structural damage inside the right wing that would have been detected if Chalk’s maintenance workers, which removed and replaced the sealant on the fuel tank, had instead looked inside the wing for hidden issues. “The establishment of repair thresholds in all maintenance programs would help ensure that repeated occurrences of a specific discrepancy would be sufficiently evaluated,” the NTSB believes.