As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF CLIMBING THROUGH 500 FEET, THE CAPTAIN NOTICED THAT THE OIL PRESSURE IN THE LEFT HAND ENGINE READ ZERO POUNDS PER SQAURE INCH. THE AIRCRAFT RETURNED TO THE AIRFIELD WITHOUT FURTHER INCIDENT. MAINTENANCE INSPECTED AND RESET THE CIRCUIT BREAKER. OPERATIONAL CHECKS WERE PERFORMED AND THE AIRCRAFT WAS RELEASED FOR SERVICE.