What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) Preliminary findings: landing at Santa Monica, CA pilot had three green lights and clearance to land, upon landing the aircraft experienced a partial nose gear collapse. Aircraft touched down on main wheels, pilot lowered nose, felt vibration and thought he had a blown nose tire. Pilot pulled back on the yoke and brought the nose up as long as he could hold it, when the nose touched down the vibration was gone (nose gear then locked down). The pilot did not realize that he had a prop strike until he shut down the engine. ATC smo tower confirmed that during the landing the aircraft appeared to have a partial gear collapse, prop strike and taxied off the runway under it's own power. Maintenance inspection found that the nose landing gear micro switch was out of rig allowing a safe gear indication, but shutting off hydraulic power and not allowing the nose gear to lock. Maintenance attempted to rig the micro switch at smo, but found that the switch bracket was adjusted to the end of its travel and the micro switch actuator spring had to be bent to properly rig the nose landing gear. This procedure is contrary to the Piper airplane maintenance manual 32-60-00 page 32. The aircraft was manufactured in 2000, has low time and maintenance records do not indicate any prior maintenance performed on the nose landing gear. The propeller was replaced, crankshaft runout checked and the aircraft was issued a special flight permit from smo to dvt (landing gear down and locked) for maintenance at cutter aviation inc., phoenix, AZ. Final report to follow pending teardown. (-23 amendment) final findings: investigation at cutter aviation inc., phoenix, AZ. Confirmed that the nose gear down limit switch for nose down light and hydraulic pump shut off was out of adjustment causing the pump to shut off and the light to indicate down with the nose gear not down and locked. The limit switch and bracket assembly was found mounted too FAR away from the down lock hook and mounted in the improper hole. A new limit switch and the existing bracket were mounted on the forward mount hole, rigged per the maintenance manual and the correct clearance was obtained. As stated in the preliminary findings a thorough search of all aircraft records were reviewed for history of prior work conducted on the landing gear system and no reference was found. It is impossible to state cause of discrepancy, this could have been a manufacturing error that manifested over time with wear or perhaps undocumented maintenance was conducted that the owner/operator was unaware of.
As the FAA filed it
(-23) PRELIMINARY FINDINGS: LANDING AT SANTA MONICA, CA PILOT HAD THREE GREEN LIGHTS AND CLEARANCE TO LAND, UPON LANDING THE AIRCRAFT EXPERIENCED A PARTIAL NOSE GEAR COLLAPSE. AIRCRAFT TOUCHED DOWN ON MAIN WHEELS, PILOT LOWERED NOSE, FELT VIBRATION AND THOUGHT HE HAD A BLOWN NOSE TIRE. PILOT PULLED BACK ON THE YOKE AND BROUGHT THE NOSE UP AS LONG AS HE COULD HOLD IT, WHEN THE NOSE TOUCHED DOWN THE VIBRATION WAS GONE (NOSE GEAR THEN LOCKED DOWN). THE PILOT DID NOT REALIZE THAT HE HAD A PROP STRIKE UNTIL HE SHUT DOWN THE ENGINE. ATC SMO TOWER CONFIRMED THAT DURING THE LANDING THE AIRCRAFT APPEARED TO HAVE A PARTIAL GEAR COLLAPSE, PROP STRIKE AND TAXIED OFF THE RUNWAY UNDER IT'S OWN POWER. MAINTENANCE INSPECTION FOUND THAT THE NOSE LANDING GEAR MICRO SWITCH WAS OUT OF RIG ALLOWING A SAFE GEAR INDICATION, BUT SHUTTING OFF HYDRAULIC POWER AND NOT ALLOWING THE NOSE GEAR TO LOCK. MAINTENANCE ATTEMPTED TO RIG THE MICRO SWITCH AT SMO, BUT FOUND THAT THE SWITCH BRACKET WAS ADJUSTED TO THE END OF ITS TRAVEL AND THE MICRO SWITCH ACTUATOR SPRING HAD TO BE BENT TO PROPERLY RIG THE NOSE LANDING GEAR. THIS PROCEDURE IS CONTRARY TO THE PIPER AIRPLANE MAINTENANCE MANUAL 32-60-00 PAGE 32. THE AIRCRAFT WAS MANUFACTURED IN 2000, HAS LOW TIME AND MAINTENANCE RECORDS DO NOT INDICATE ANY PRIOR MAINTENANCE PERFORMED ON THE NOSE LANDING GEAR. THE PROPELLER WAS REPLACED, CRANKSHAFT RUNOUT CHECKED AND THE AIRCRAFT WAS ISSUED A SPECIAL FLIGHT PERMIT FROM SMO TO DVT (LANDING GEAR DOWN AND LOCKED) FOR MAINTENANCE AT CUTTER AVIATION INC., PHOENIX, AZ. FINAL REPORT TO FOLLOW PENDING TEARDOWN. (-23 AMENDMENT) FINAL FINDINGS: INVESTIGATION AT CUTTER AVIATION INC., PHOENIX, AZ. CONFIRMED THAT THE NOSE GEAR DOWN LIMIT SWITCH FOR NOSE DOWN LIGHT AND HYDRAULIC PUMP SHUT OFF WAS OUT OF ADJUSTMENT CAUSING THE PUMP TO SHUT OFF AND THE LIGHT TO INDICATE DOWN WITH THE NOSE GEAR NOT DOWN AND LOCKED. THE LIMIT SWITCH AND BRACKET ASSEMBLY WAS FOUND MOUNTED TOO FAR AWAY FROM THE DOWN LOCK HOOK AND MOUNTED IN THE IMPROPER HOLE. A NEW LIMIT SWITCH AND THE EXISTING BRACKET WERE MOUNTED ON THE FORWARD MOUNT HOLE, RIGGED PER THE MAINTENANCE MANUAL AND THE CORRECT CLEARANCE WAS OBTAINED. AS STATED IN THE PRELIMINARY FINDINGS A THOROUGH SEARCH OF ALL AIRCRAFT RECORDS WERE REVIEWED FOR HISTORY OF PRIOR WORK CONDUCTED ON THE LANDING GEAR SYSTEM AND NO REFERENCE WAS FOUND. IT IS IMPOSSIBLE TO STATE CAUSE OF DISCREPANCY, THIS COULD HAVE BEEN A MANUFACTURING ERROR THAT MANIFESTED OVER TIME WITH WEAR OR PERHAPS UNDOCUMENTED MAINTENANCE WAS CONDUCTED THAT THE OWNER/OPERATOR WAS UNAWARE OF.