 The first production F6U @-@ 1 performed its initial flight on 29 June 1949 , and 20 of the aircraft were provided to VX @-@ 3 , an operational evaluation squadron based at Naval Air Station Patuxent River in Maryland . The judgment from the evaluation was that the Pirate was unacceptable for operational use . Naval aviators disparagingly called the F6U the " groundhog " . On 30 October 1950 , BuAer informed Vought of the Navy 's opinion of the Pirate in terms both bureaucratic and scathing : " The F6U @-@ 1 had proven so sub @-@ marginal in performance that combat utilization is not feasible . " 
