20160903014929I

Aircraft was operating on a pleasure flight flying from dvt out to wickenburg and indian wells. As the flight headed north toward alamo lake the pilot decided to land at a local airport. When he executed the ?before landing? Checklist the gear did not extend normally. Specifically the right hand (RH) gear leg did not extend when the other gear extended.

The pilot stated he climbed out of the airport area and attempted to cycle the gear several times with the regular operating system as well as the emergency system. The RH gear did not respond (drop free from gear well) during any of the attempts. The pilot opted to return to dvt to ensure there were emergency response vehicles available. During the return flight to dvt the pilot attempted multiple methods of extending the gear (slow flight, positive & negative g?s, steep turns) with no change to the RH gear position. The pilot flew the aircraft for most of an hour attempting to get gear to extend. Finally he notified tower that they would be making a gear up landing.

The aircraft was cleared to do an emergency gear up landing on rwy 25L and the pilot performed a successful landing. The aircraft touched down on the runway causing damage only to the aircraft belly and door skins, and the propeller. No one aboard the aircraft was injured.

The aircraft was picked up to transport it off of the runway area. While the aircraft was clear of the ground maintenance personnel noted that the up-lock pin on the RH gear mechanism was broken and would not allow the gear leg to disengage from the gear lock assembly. Once the leg was freed from the lock assembly the RH gear was able to extend.

Gear was then hand pumped into the fully extended and locked position. The aircraft was lowered to the ground and was able to be towed to the hanger.

Upon visual inspection of the aircraft landing gear this inspector was able to verify that the clevis pin attaching the rod end of the landing gear lock assembly to the gear actuator assembly was missing. There was no clevis pin or safety cotter pin found in the gear well area. Further discussion with the owner revealed that this aircraft had been sitting for almost 20 years (mothballed) and recently had been returned to service after an annual inspection on may 27, 2016. Extensive maintenance had been performed to the aircraft for the inspection. Maintenance records indicate a gear retraction system was serviced and retraction/extension test was performed several times using a hydraulic mule as well as the a/c emergency hand pump. All gear cycles performed normally with no hydraulic leaks indicated. Other than replacement of landing gear hoses, no other maintenance was performed on the gear system during the inspection.

The owner stated that the aircraft had flown several times since the annual inspection and no retraction problems had occurred prior to this flight. The owner and his son were aboard the aircraft on this flight. The aircraft has flown 8.45 hours since the last annual inspection.