What was found
DURING CRUISE FLIGHT, AT 21,000’ THE PILOT NOTICED THE RED LT & RT HYD PRESS WARNING LIGHTS ILLUMINATED. THE PILOT CHECKED HIS HYD PRESS GAUGE & IT WAS FLUCTUATING BETWEEN 500 & 1500 PSI FOR 5 SECONDS & THEN WENT TO 0. THE PILOT NOTIFIED THE TOWER OF THE SITUATION & DECLARED AN EMER, THE PILOT FOLLOWED THE EMER PROCEDURES IN THE PILOT OPERATING MANUAL. PERFORMED MANUAL EXTENSION OF LANDING GEAR. THE PILOT RETURNED & LANDED WITHOUT INCIDENT. INSPECTION REVEALED A LEAKING HYD LINE ON RT SIDE OF HYD POWER PACK. REPLACED LINE & PERFORMED FUNCTIONAL CHECK OF LANDING GEAR SYS. ALL CHECKS WERE NORMAL.