Narrative:

En route to destination, cruising at FL270. Captain noticed hydraulic quantity in the #3 system was lower than normal. This situation does not give any other indication in cockpit but the synoptic page showed the quantity as white instead of green. After speaking with maintenance, as long as quantity was steady (which it was) and pump pressures were good (which they were), no action was necessary and maintenance would greet the aircraft at the destination. As the descent was commenced into the destination, the fluid quantity decreased further. We were cleared for the approach to runway 5 and GS intercept, the landing gear was selected down. The system fluid then decreased to zero and the nosewheel came down and locked, but the gear did not. A landing gear warning and hydraulic caution were soon heard. The first officer initiated and flew a go around and then the captain ran through the appropriate checklists. The gear had to be extended manually. It indicated that all 3 gear were down and locked. The only real concern at this point was that there would be no nosewheel steering upon landing and only 1/2 the brake system would be working. An adjusted landing distance was calculated and the runway was more than long enough. The captain then took over flying and an uneventful landing was made and the aircraft stopped on the runway. A tug was then called to tow us to the gate. Hydraulic fluid was seen leaking from the fuselage bottom on the postflt. The mechanic later found at least 3 leaks in the system. It would have been nice for there to be some sort of warning that the hydraulic fluid was low enough, required a diversion or gear extension to assure the gear extended normally. Callback conversation with reporter revealed the following information: the reporter stated when on the ground, the gate technician reported 3 separate hydraulic leaks in lines and fittings but did not disclose their location. The reporter also said this airplane should be equipped with a hydraulic reservoir low level warning system.

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Original NASA ASRS Text

Title: A CANADAIR CL65 ON FINAL APCH AT 3000 FT EXECUTED A GAR DUE TO LOSS OF #3 MAIN HYD SYS. LNDG GEAR EXTENDED MANUALLY. CAUSED BY LEAKING LINES AND FITTINGS.

Narrative: ENRTE TO DEST, CRUISING AT FL270. CAPT NOTICED HYD QUANTITY IN THE #3 SYS WAS LOWER THAN NORMAL. THIS SIT DOES NOT GIVE ANY OTHER INDICATION IN COCKPIT BUT THE SYNOPTIC PAGE SHOWED THE QUANTITY AS WHITE INSTEAD OF GREEN. AFTER SPEAKING WITH MAINT, AS LONG AS QUANTITY WAS STEADY (WHICH IT WAS) AND PUMP PRESSURES WERE GOOD (WHICH THEY WERE), NO ACTION WAS NECESSARY AND MAINT WOULD GREET THE ACFT AT THE DEST. AS THE DSCNT WAS COMMENCED INTO THE DEST, THE FLUID QUANTITY DECREASED FURTHER. WE WERE CLRED FOR THE APCH TO RWY 5 AND GS INTERCEPT, THE LNDG GEAR WAS SELECTED DOWN. THE SYS FLUID THEN DECREASED TO ZERO AND THE NOSEWHEEL CAME DOWN AND LOCKED, BUT THE GEAR DID NOT. A LNDG GEAR WARNING AND HYD CAUTION WERE SOON HEARD. THE FO INITIATED AND FLEW A GAR AND THEN THE CAPT RAN THROUGH THE APPROPRIATE CHECKLISTS. THE GEAR HAD TO BE EXTENDED MANUALLY. IT INDICATED THAT ALL 3 GEAR WERE DOWN AND LOCKED. THE ONLY REAL CONCERN AT THIS POINT WAS THAT THERE WOULD BE NO NOSEWHEEL STEERING UPON LNDG AND ONLY 1/2 THE BRAKE SYS WOULD BE WORKING. AN ADJUSTED LNDG DISTANCE WAS CALCULATED AND THE RWY WAS MORE THAN LONG ENOUGH. THE CAPT THEN TOOK OVER FLYING AND AN UNEVENTFUL LNDG WAS MADE AND THE ACFT STOPPED ON THE RWY. A TUG WAS THEN CALLED TO TOW US TO THE GATE. HYD FLUID WAS SEEN LEAKING FROM THE FUSELAGE BOTTOM ON THE POSTFLT. THE MECH LATER FOUND AT LEAST 3 LEAKS IN THE SYS. IT WOULD HAVE BEEN NICE FOR THERE TO BE SOME SORT OF WARNING THAT THE HYD FLUID WAS LOW ENOUGH, REQUIRED A DIVERSION OR GEAR EXTENSION TO ASSURE THE GEAR EXTENDED NORMALLY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED WHEN ON THE GND, THE GATE TECHNICIAN RPTED 3 SEPARATE HYD LEAKS IN LINES AND FITTINGS BUT DID NOT DISCLOSE THEIR LOCATION. THE RPTR ALSO SAID THIS AIRPLANE SHOULD BE EQUIPPED WITH A HYD RESERVOIR LOW LEVEL WARNING SYS.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.