Narrative:

I was the PF and was told to maintain 170 KTS to marker. Just outside the marker, I called for gear down. Captain lowered gear handle. I didn't hear the lowering of the gear, so I looked over to gear handle when I heard a tremendous thud and we got 3 green. I assumed the gear had been frozen due to moisture from midwest ice storm. A few seconds later we got a right hydraulic low pressure light due to loss of right system. Declared emergency, followed checklist and landed uneventfully. Stopped on runway, had gear pinned and were towed to gate. Callback conversation with reporter revealed the following information: the reporter stated the gear extension did not sound normal when the gear handle was placed to 'down.' the reporter said no rush of air then a loud thud that shook the aircraft and disconnected the autoplt. The reporter said 135 KTS was maintained and an uneventful landing was made. The reporter stated the cause of the hydraulic system loss was the failure of the nose landing gear retract actuator.

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Original NASA ASRS Text

Title: A DC9-30 ON APCH AT 4000 FT DECLARED AN EMER DUE TO COMPLETE LOSS OF THE R HYD SYS PRESSURE AND QUANTITY CAUSED BY A FAILED NOSE GEAR RETRACT ACTUATOR.

Narrative: I WAS THE PF AND WAS TOLD TO MAINTAIN 170 KTS TO MARKER. JUST OUTSIDE THE MARKER, I CALLED FOR GEAR DOWN. CAPT LOWERED GEAR HANDLE. I DIDN'T HEAR THE LOWERING OF THE GEAR, SO I LOOKED OVER TO GEAR HANDLE WHEN I HEARD A TREMENDOUS THUD AND WE GOT 3 GREEN. I ASSUMED THE GEAR HAD BEEN FROZEN DUE TO MOISTURE FROM MIDWEST ICE STORM. A FEW SECONDS LATER WE GOT A R HYD LOW PRESSURE LIGHT DUE TO LOSS OF R SYS. DECLARED EMER, FOLLOWED CHKLIST AND LANDED UNEVENTFULLY. STOPPED ON RWY, HAD GEAR PINNED AND WERE TOWED TO GATE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE GEAR EXTENSION DID NOT SOUND NORMAL WHEN THE GEAR HANDLE WAS PLACED TO 'DOWN.' THE RPTR SAID NO RUSH OF AIR THEN A LOUD THUD THAT SHOOK THE ACFT AND DISCONNECTED THE AUTOPLT. THE RPTR SAID 135 KTS WAS MAINTAINED AND AN UNEVENTFUL LNDG WAS MADE. THE RPTR STATED THE CAUSE OF THE HYD SYS LOSS WAS THE FAILURE OF THE NOSE LNDG GEAR RETRACT ACTUATOR.

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.