As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT CRUISE ALTITUDE 2500 FT MSL, COCKPIT BEGAN TO FILL WITH SMOKE. HYD AND SERVO LIGHTS ON CAUTION PANEL ILLUMINATED. REDUCED AIRSPEED AND MADE EMERGENCY LANDING. AFTER LANDING AND ENGINE SHUTDOWN THE PRIMARY HYD BELT WAS FOUND BROKE AND MISSING. NO OTHER ACFT DAMAGE WAS NOTED. MECHANIC INSPECTED THE ACFT AND FOUND THE HYD PUMP DRIVE ASSEMBLY HAD FAILED CAUSING THE BELT TO BREAK. REPLACED THE PUMP DRIVE ASSY TO INCLUDE A NEW BELT WITH NO ADDITIONAL DEFECTS. THE ACFT WAS RETURNED TO SERVICE AND FLOWN BACK TO ITS BASE OF OPERATION.