As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING FLIGHT, BOTH HYDRAULIC LIGHTS ILLUMINATED. THE AIRCRAFT RETURNED TO BASE AND HAD TO USE EMERGENCY LANDING GEAR EXTENSION PROCEDURES. AFTER AN UNEVENTFUL LANDING, MAINTENANCE PERSONNEL FOUND A LOOSE AND LEAKING B NUT ONTHE HYDRAULIC RESERVOIR (POWER PACK).