20190819013959I

The pilot initiated a low level balked landing, advising the tower that "I'm not sure my gear is down properly"" and as he passed the tower, he mentioned he was not getting a green gear indication. The controller replied that the gear appeared down, but that he couldn't tell if they were locked, asking the PIC if he wanted the emergency equipment, or another flyby to get a better look. The pilot declined both and proceeded at a low altitude in right traffic. The pilot stated that it was a burnt out gear indication bulb, and was cleared for the option, and the controller again asked if the PIC wanted crash equipment or another tower flyby to get a better look at the gear, which the pilot declined again. According to witnesses, the aircraft touched down with the right main gear swinging freely unlocked, and the aircraft veered off the right side of runway 28R, the right wing contacting the ground and pulling the aircraft in a right semicircle, coming to rest on the edge of the parallel taxiway with the nose pointing on a heading of 100 degrees. Multiple A&P mechanic witnesses working in a large open hangar adjacent to the right side of runway 28R stated that the aircraft made its first approach to land with the right main gear observed hanging down unlocked, and that the left main gear and nose gear appeared to be locked in the down position. They stated the aircraft executed a balked landing from a low altitude, and immediately proceeded low around the pattern, making another approach and touchdown with the right main gear still dangling unlocked. ATC audio tapes only picked up a gear warning horn on the pilots mike after the aircraft had slid to a stop, during the final radio contact with the pilot prior to his egress. The right wing sustained leading edge downward twisting deformation, the right upper wing skin forward of the aileron was buckled, the right lower vertical stabilizer was crushed by ground contact, and the right tire and tube was destroyed. NTSB originally classified as accident WPR19LA229. Later downgraded to incident after further investigation of damage by mechanic. A crane was used to lift the aircraft, and mechanics freely swung the right main gear into the locked down position, and towed the aircraft down the taxiway to parking on its wheels. The next day upon examination, a puddle of hydraulic fluid was observed to be dripping from the belly below the right main gear actuator, and puddling inside the right main gear leg door. The hydraulic power pack reservoir was found to be nearly full of clean H5606 hydraulic fluid, and the emergency gear extension handle was found stowed. Maintenance records review showed that the aircraft had recently been inspected in accordance with an annual inspection, and no records of any installation of the unapproved home window air conditioning unit or inverter found within the cabin and interconnected directly to the main electrical buss, were found. The inline circuit breaker for the unapproved air conditioner system was found engaged at the scene, indicating it was operating during the landing, loading the electrical system, and not allowing the full hydraulic system pressure to be developed to fully extend the final landing gear leg.