20230322006839A

The pilot of a PA-18AS-125 was on a normal recreational flight in and around the Umatilla, FL area. The aircraft is equipped for both water and runway landings. With that, the pilot stated he flew from his home base to Umatilla airport (X23) for fuel. While fueling he observed a small hydraulic leak near the gear area, however, could not substantiate its whereabouts and the amount not alarming. With checks performed no defects were noted. Therefore, he departed and was returning to his home at crescent lake, FL when upon slowing the aircraft for touchdown and contacting the water, the aircraft nosed over and went inverted. The aircraft was removed with no damage to property or the waterway. The aircraft was brought to the hangar and preliminary investigation had shown that the right extendable gear leg did not retract. The pilot stated he did not notice any abnormal flight characteristics or drag during his return and may not have had a good indication of the position. The whipaire 2100A float system installed was recently inspected during the annual on 11/24/2022 with no defects noted. The design is for the leg to pull back and into the float assembly with assist from electro powered magnetic switches. Upon further examination of the pump, it had shown an area containing an abrasion however is believed to be from a wobble effect. However, when looking at the sealing surface or, top seal and with the potential wobble may have distorted the seal allowing fluid leakage during activation. There is no apparent reason as to why the seal started to leak and could be due to inactivity or the wearing of the sealing surfaces while activating the hand pump. The pump itself provides 700 PSI to cycle the gear and has a relief valve for overpressure situations. But as the placard states you can damage the pump by exerting too much pressure on the system and was said not to be the case. With further examination found the o-ring deteriorated and cut, these things would not be seen during normal inspection. The fluid level was satisfactory. The aircraft sustained damage to the right-wing struts and braces, but no damage was noted to the inboard mounting surfaces and or attach points and did show any signs of flexing. However further inspection of both wings and their structure must be determined. The wing fabric covering sustained significant water damage with associated wrinkling, and the wing braces were pushed up and into the surface covering. The nose cowling sustained some buckling near and around the propeller hub, and the underside of the engine cowling also buckled. The engine and mounts appeared fine. Most gauges sustained water damage and serviceability will be determined. The flight control surfaces were intact and no damage to the floats and the left leg operated normally and was retracted. The pilot without indication could not clearly see whether the gear was retracted or extended other than an indication whether indicated or having a position error. It is this inspector’s opinion that the hand pump designed to lower and lift the gear legs from the floats became intermittent without the pilot having a proper indication or otherwise therefore, failed and no further action is required of the pilot.