NTSB co-pilot denies reports of cockpit argument . ( CNN ) -- NTSB flight overshot Minnesota by about 150 miles . NTSB investigating about 7:56 ET Wednesday night of radio silence . Flight crew cooperative and sober , police report says .
NTSB co-pilot denies reports of cockpit argument . NTSB flight overshot Minnesota by about 150 miles . NTSB investigating about 7:56 ET Wednesday night of radio silence . Flight crew cooperative and sober , police report says .