As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT RETURNED BACK TO SDF DUE TO AIRCRAFT DOES NOT PRESSURIZE IN AUTO. OPENED EMERGENCY VALVE, COCKPIT FILLED WITH SMOKE. RADAR SHORTS OUT AND IS INTERMITTENT. NR 2 COMM DOES NOT TRANSMIT. REMOVED AND REPLACED CABIN ALTITUDE CONTROLLER. PRESSURIZATION SYSTEM OPS CHECK GOOD AT THIS TIME AND UNABLE TO DUPLICATE ON GROUND. (X)