Narrative:

At approximately XA30 in crw, our planned departure was completed and I selected gear up. I then switched gear down and up again, since the possibility of slush or other moisture could freeze the gear. I received normal gear indications except that when gear was selected up for the second time, the handle did not return to neutral and had a red warning light indicating a possible problem with the inboard gear doors. I requested and received clearance for low approach. Crw tower indicated the right inboard door remain open. I received clearance to land and did so with normal indications after 'gear down' was selected. An uneventful landing, taxi, and shutdown proceeded. I visually inspected the gear for ice or anything else. I found the right inboard door open. After deliberating, I decided since this was the only thing abnormal, I would proceed to home base, newark-heath, oh, for unscheduled maintenance. Procedures would remain normal with the exception of remaining at all times below maximum gear down speed of 153 KIAS for structural reasons. Upon departure, all system operated normally. I selected gear down and up and again received normal indications. I decided we would proceed to original destination of sgh. At cruise, the red warning light illuminated and I continued as planned to sgh at less than 153 KIAS. Descending and receiving visual approach clearance, I selected gear down. The aircraft yawed and no green light for the right main landing gear was seen. I cycled the gear numerous times to no avail. After 2 low passes, visual confirmation was received that the right gear was 'partially hanging down.' I picked up my final IFR clearance to home, vta (newark-heath, oh). After leveloff at 5000 ft, I engaged the autoplt and began calling vta unicom to relay my situation. I began emergency gear extension procedures, but when I extended the emergency gear extension handle, it was frozen in place and unmovable. I had nothing to lose, so I broke it free and had full motion, but no resistance at all. This motion revealed no pressure and gear down motion. I instructed my passenger to situation in the back facing rearward and briefed him on emergency egress procedures. I asked columbus approach to call the FBO at vta and the fire department. I again cycled the gear a number of times as one last ditch effort, to no avail. I briefed the passenger on my intention to complete the sdf approach to runway 9 at vta and circle for runway 27. I exited the pilot door and my way to the cabin door and exited my passenger. Both passenger and myself were completely unharmed. After the aircraft was raised up to lower the gear, the mechanic disconnected the hydraulic line and discovered the line blocked with ice. After melting it with a blowtorch, the gear released and extended. There is no explanation why there was water in my hydraulic system. I have no doubt that the same incident would be reached sometime in the future possibly with worse end results. There is no maintenance inspection calling for checking the integrity of the hydraulic fluid, ever -- only to add fluid as needed. To prevent this from happening again, I shall see to it that the hydraulic system is purged of all fluid before servicing with military specification hydraulic fluid and will do so on an annual basis.

Google
 

Original NASA ASRS Text

Title: A PIPER PA31 EXECUTED AN EMER LNDG WITH THE R MAIN LNDG GEAR NOT EXTENDED, CAUSED BY WATER CONTAMINATED HYD FLUID.

Narrative: AT APPROX XA30 IN CRW, OUR PLANNED DEP WAS COMPLETED AND I SELECTED GEAR UP. I THEN SWITCHED GEAR DOWN AND UP AGAIN, SINCE THE POSSIBILITY OF SLUSH OR OTHER MOISTURE COULD FREEZE THE GEAR. I RECEIVED NORMAL GEAR INDICATIONS EXCEPT THAT WHEN GEAR WAS SELECTED UP FOR THE SECOND TIME, THE HANDLE DID NOT RETURN TO NEUTRAL AND HAD A RED WARNING LIGHT INDICATING A POSSIBLE PROB WITH THE INBOARD GEAR DOORS. I REQUESTED AND RECEIVED CLRNC FOR LOW APCH. CRW TWR INDICATED THE R INBOARD DOOR REMAIN OPEN. I RECEIVED CLRNC TO LAND AND DID SO WITH NORMAL INDICATIONS AFTER 'GEAR DOWN' WAS SELECTED. AN UNEVENTFUL LNDG, TAXI, AND SHUTDOWN PROCEEDED. I VISUALLY INSPECTED THE GEAR FOR ICE OR ANYTHING ELSE. I FOUND THE R INBOARD DOOR OPEN. AFTER DELIBERATING, I DECIDED SINCE THIS WAS THE ONLY THING ABNORMAL, I WOULD PROCEED TO HOME BASE, NEWARK-HEATH, OH, FOR UNSCHEDULED MAINT. PROCS WOULD REMAIN NORMAL WITH THE EXCEPTION OF REMAINING AT ALL TIMES BELOW MAX GEAR DOWN SPD OF 153 KIAS FOR STRUCTURAL REASONS. UPON DEP, ALL SYS OPERATED NORMALLY. I SELECTED GEAR DOWN AND UP AND AGAIN RECEIVED NORMAL INDICATIONS. I DECIDED WE WOULD PROCEED TO ORIGINAL DEST OF SGH. AT CRUISE, THE RED WARNING LIGHT ILLUMINATED AND I CONTINUED AS PLANNED TO SGH AT LESS THAN 153 KIAS. DSNDING AND RECEIVING VISUAL APCH CLRNC, I SELECTED GEAR DOWN. THE ACFT YAWED AND NO GREEN LIGHT FOR THE R MAIN LNDG GEAR WAS SEEN. I CYCLED THE GEAR NUMEROUS TIMES TO NO AVAIL. AFTER 2 LOW PASSES, VISUAL CONFIRMATION WAS RECEIVED THAT THE R GEAR WAS 'PARTIALLY HANGING DOWN.' I PICKED UP MY FINAL IFR CLRNC TO HOME, VTA (NEWARK-HEATH, OH). AFTER LEVELOFF AT 5000 FT, I ENGAGED THE AUTOPLT AND BEGAN CALLING VTA UNICOM TO RELAY MY SIT. I BEGAN EMER GEAR EXTENSION PROCS, BUT WHEN I EXTENDED THE EMER GEAR EXTENSION HANDLE, IT WAS FROZEN IN PLACE AND UNMOVABLE. I HAD NOTHING TO LOSE, SO I BROKE IT FREE AND HAD FULL MOTION, BUT NO RESISTANCE AT ALL. THIS MOTION REVEALED NO PRESSURE AND GEAR DOWN MOTION. I INSTRUCTED MY PAX TO SIT IN THE BACK FACING REARWARD AND BRIEFED HIM ON EMER EGRESS PROCS. I ASKED COLUMBUS APCH TO CALL THE FBO AT VTA AND THE FIRE DEPT. I AGAIN CYCLED THE GEAR A NUMBER OF TIMES AS ONE LAST DITCH EFFORT, TO NO AVAIL. I BRIEFED THE PAX ON MY INTENTION TO COMPLETE THE SDF APCH TO RWY 9 AT VTA AND CIRCLE FOR RWY 27. I EXITED THE PLT DOOR AND MY WAY TO THE CABIN DOOR AND EXITED MY PAX. BOTH PAX AND MYSELF WERE COMPLETELY UNHARMED. AFTER THE ACFT WAS RAISED UP TO LOWER THE GEAR, THE MECH DISCONNECTED THE HYD LINE AND DISCOVERED THE LINE BLOCKED WITH ICE. AFTER MELTING IT WITH A BLOWTORCH, THE GEAR RELEASED AND EXTENDED. THERE IS NO EXPLANATION WHY THERE WAS WATER IN MY HYD SYS. I HAVE NO DOUBT THAT THE SAME INCIDENT WOULD BE REACHED SOMETIME IN THE FUTURE POSSIBLY WITH WORSE END RESULTS. THERE IS NO MAINT INSPECTION CALLING FOR CHKING THE INTEGRITY OF THE HYD FLUID, EVER -- ONLY TO ADD FLUID AS NEEDED. TO PREVENT THIS FROM HAPPENING AGAIN, I SHALL SEE TO IT THAT THE HYD SYS IS PURGED OF ALL FLUID BEFORE SVCING WITH MIL SPEC HYD FLUID AND WILL DO SO ON AN ANNUAL BASIS.

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.