LEAR 60 FLT CREW HAS HYD SYS MALFUNCTION AND DIVERTS TO YYY.

Narrative

A LEAR 60 WAS RETURNED TO SVC WITH ALL PROPER DOCUMENTS FROM QUALITY CTL. AT THIS TIME; COMPANY Y PF MR X (ASSISTANT CHIEF PLT/MAINT OFFICER) AND PNF MR Y (CHIEF PLT) PERFORMED A STANDARD EXTERIOR AND INTERIOR PREFLT PER AFM WITH NO DEFECTS NOTED. AFTER FURTHER NORMAL PREFLT DUTIES; FUELING; WX BRIEFING; FILING AN IFR FLT PLAN; THE CREW DEPARTED FLL WITH 2 CREW MEMBERS; AND 2 PAX ENRTE TO HOME BASE OF ZZZ. TKOF; CLB AND CRUISE FLT WERE PERFECTLY NORMAL WITH NO ANOMALIES. AT APPROX 90 NM FROM THE DEST OF ZZZ; THE CREW ASKED FOR AND RECEIVED A CLRNC TO START THE ENRTE DSCNT. SHORTLY THEREAFTER; THE PF RPTED A MASTER CAUTION LIGHT WITH 2 AMBER HYD LIGHTS OSCILLATING ON AND OFF VERY FAST. IMMEDIATELY; THE CREW CHKED THE HYD PRESSURE; PER THE ABNORMAL HYD PRESSURE LIGHT(S) CHKLIST; AND FOUND THE HYD PRESSURE NORMAL. A DECISION WAS MADE AT THIS TIME TO DIVERT TO AN ARPT WITH A LONGER RWY; THE CREW NOT KNOWING IF THIS WAS AN INDICATOR PROB OR A REAL HYD PROB. AT THIS TIME THE CREW DECIDED TO RUN THE HYD SYS FAILURE/ALTERNATE GEAR EXTENSION CHKLIST. WHILE MOVING THE FLAP SELECTOR TO 8 DEGS; THE CREW NOTED A DECREASE IN THE HYD PRESSURE. IT WAS AT THIS POINT THE CREW KNEW THIS WAS NOT AN INDICATOR PROB; BUT A REAL INDICATION OF A HYD MALFUNCTION OR LEAK. CONTINUING WITH THE CHKLIST; THE CREW WAS ABLE TO EXTEND THE MAIN LNDG GEAR NORMALLY; BUT HYD PRESSURE WAS ERRATIC. THE CREW KNEW THIS WAS A CONDITION OF URGENCY AND ELECTED TO DECLARE AN EMER AND CLRNC TO YYY BECAUSE PER THE CHKLIST; NORMAL LNDG DISTANCES SHOULD BE INCREASED BY A FACTOR OF 3. WHILE ENRTE TO YYY; THE CREW FOLLOWED THE 'HYD SYS FAILURE LNDG' CHKLIST AND WAS ABLE TO EXTEND FLAPS TO ABOUT 30 DEGS OR 80% OF NORMAL LNDG FLAPS. NOTED BY THE CREW DURING EXTENSION OF THE MAIN LNDG GEAR AND FLAPS; THAT THE HYD PRESSURE WOULD FALL WELL BELOW THE NORMAL OPERATING RANGE; AND RETURN TO APPROX 1/2 NORMAL AFTER ACTUATION HAD BEEN COMPLETED. WHILE IN THE RADAR PATTERN FOR AN ILS TO RWY 13L AT YYY; THE ABNORMAL HYD SYS FAILURE LNDG CHKLIST WAS COMPLETED. THE ACFT BROKE OUT OF IMC AT APPROX 700 FT AGL. TOUCHDOWN WAS NORMAL AND PNEUMATIC BRAKING WAS APPLIED; STOPPING THE ACFT IN APPROX 5800 FT OF THE 10000 FT AVAILABLE. IT WAS NOTICED AT THIS TIME BY THE PNF (AFTER ROLLOUT AND THE ACFT WAS STOPPED); THE RED FIRE ANNUNCIATOR ON THE APU ILLUMINATED BRIEFLY 2 TIMES; AND THEN REMAINED ON. THE PNF ACTIVATED THE APU HALON FIRE BOTTLE; AND STARTED AN EVAC OF THE 2 PAX. THE FO SECURED THE ACFT IN PLACE AND EXITED THE ACFT BUT NOTED NO SECONDARY INDICATIONS OF AN APU FIRE SUCH AS BLEED AIR LIGHTS ON THE ANNUNCIATOR PANEL OR A CALL FROM THE TWR OR FIRE BOSS ON FREQ. THE FIRE BOSS INSPECTED THE ACFT AND DECLARED THE ACFT AS FIRE SAFE. WITH THE PAX SAFE; THE CREW INSPECTED THE ACFT AND NOTED THE #1 MAIN LNDG GEAR TIRE FLAT SPOTTED; AND A LARGE AMOUNT OF HYD FLUID ON THE R SIDE OF THE FUSELAGE EMANATING FROM THE R WHEEL WELL AREA. AT THIS POINT; THE ACFT WAS TOWED CLR OF THE RWY AND STORED FOR THE NIGHT.