As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ON TAKEOFF 'A' SYSTEM QTY INDICATED ZERO. MAIN GEAR EVENTUALLY RETRACTED BECAUSE IT WAS ALREADY SELECTED UP. 'A' SYSTEM CYCLED ON AND OFF SEVERAL TIMES AND INDICATED 200 PSI. EMERGENCY DECLARED AND LANDING CARRIED OUT. PRESSURE LINE 'B' NUT LOOSE, TIGHTENED.