A PIPER PA23 MADE AN EMER LNDG DUE TO THE R MAIN LNDG GEAR FAILED TO EXTEND. CAUSED BY A CRACKED R MAIN GEAR SOLID HYD LINE.

Narrative

DEPARTED LAKE HAUASU; A FUEL STOP ENRTE FROM ASPEN; CO. IFR TO MONTGOMERY FIELD; GEAR WAS ABOUT 3-5 SECONDS SLOW TO RETRACT FULLY. MADE MENTAL NOTE TO CHK HYD FLUID LEVEL AT MYF. DSNDED TO 4000 FT; VECTORS TO ILS RWY 28R AT MYF WITH ATIS INFO. CLRED FOR APCH; INTERCEPT HDG. AS I APCHED THE LOC; I LOWERED FLAPS TO 1/4 DEG. THEY FELT BOUNCY. I INTERCEPTED LOC; APCHING GLIDE PATH; LOWERED GEAR HANDLE; NOTHING HAPPENED. I USED THE HAND PUMP; BUT IT DID NOT OFFER ITS USUAL RESISTANCE; AND WAS NO HELP. I WAS ABLE TO RAISE THE FLAPS BACK UP. AFTER HOLDING IN A R-HAND PATTERN OVER RWY 28R AND READING POH PROCS; WHILE CHKING CIRCUIT BREAKERS; ETC; IT APPEARED THE CO2 BLOWDOWN WAS THE NEXT STEP. A FIRM PULL ON THE CO2 ACTIVATION RING BROUGHT AN LM.6 SAFE; WITH N6 AND RMG UNSAFE. THE UNSAFE N6 WAS VISUALLY VERIFIED BY PLT WITH MIRROR ON L ENG COWL. LNDG CONFIGN WAS NOW DETERMINED; AS IT WAS NOT POSSIBLE TO RAISE GEAR AFTER A CO2 BLOWDOWN. A LARGER RWY NOT REQUIRED AND BY THIS TIME THE EMER RESPONSE TEAM WAS IN PLACE ON THE ARPT. I SHUT DOWN BOTH ENGS; FUEL OFF; FEATHERED PROPS; TRIED TO LEVEL 2 BLADED PROPS. I TOUCHED DOWN ON L GEAR; HELD UP R WING AND NOSE UNTIL 60 KTS OR SO; THEN GENTLY LOWERED R WING TO RWY. AS I FEARED; GEAR COLLAPSED (N6 AND R MAIN LNDG GEAR) WHILE L MAIN GEAR HELD LINE. I USED RUDDER AND BRAKE TO HOLD ACFT STRAIGHT. WHEN I HAD A FREE MICROSECOND; I SECURED MASTER SWITCH. AS THE ACFT GND TO A HALT; IT TURNED ABOUT 25 DEGS TO THE R. WHEN ALL MOVEMENT STOPPED MY WIFE COULD NOT OPEN THE CABIN DOOR. I TRIED AND COULD NOT. EGRESS WAS MADE THROUGH REAR EMER EXIT WINDOW. THIS ACFT HAS PRIOR SLOW RETRACTIONS WITH UNEVENTFUL LNDG GEAR EXTENSIONS MANY TIMES. THE HYD FLUID 'MAY JUST BE A LITTLE LOW' DUE TO WHATEVER MINOR LEAKS OR FLUID LOSSES CANNOT BE DETECTED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE FAILURE OF THE R MAIN LNDG GEAR TO EXTEND USING THE NORMAL SYS AND THE 2 BACKUP SYS WAS A CRACKED SOLID HYD LINE LOCATED ON THE R MAIN LNDG GEAR. THE RPTR SAID THE NTSB HAS REMOVED AND TAKEN THE LINE TO DETERMINE THE FAILURE MODE USING AN ELECTRON MICROSCOPE. THE RPTR STATED THE CONCERN OVER THIS FAILED LINED IS ITS FUNCTION IN THE NORMAL OP AND THE 2 GEAR BACKUP SYS.