NTSB Issues Safety Recommendation to FAA Regarding Stall Angle of Attack in Ground Effect

The National Transportation Safety Board has issued a safety recommendation, identified as A-12-054 and associated with NTSB number DCA11MA076. This directive is addressed to the Federal Aviation Administration. The board instructs the agency to inform both domestic and foreign manufacturers of airplanes certified under 14 Code of Federal Regulations Parts 23 and 25. These manufacturers are advised to consider the circumstances of the referenced accident when estimating an airplane’s stall angle of attack in ground effect. Specifically, the recommendation highlights the possibility that the airplane’s maximum lift coefficient in ground effect could be lower than its maximum lift coefficient in free air. This guidance aims to ensure that certification processes account for these aerodynamic variations to enhance safety standards.