Incident Overview
On June 25, 2017, at approximately 1310 Pacific daylight time, a Lake LA-4 airplane, registration N7628L, was substantially damaged during a landing accident near Byron, California. The pilot and passenger were not injured. The flight was conducted as a personal flight under Title 14 Code of Federal Regulations Part 91.
Pilot Report
The pilot reported that during the approach for landing, he extended the flaps fully. Once established on the approach, he performed pre-landing checks, including a visual inspection of the landing gear, which appeared normal. The airplane touched down normally, and the pilot could feel all three wheels on the ground. Subsequently, the airplane began to sink to the right, followed by a right yaw, and then it veered off the right side of the runway.
Postaccident Examination
A postaccident examination revealed that the nose landing gear and the right main landing gear had collapsed, and the keel was substantially damaged.
Landing Gear System History
The pilot reported experiencing issues with the landing gear microswitches failing to close properly on previous flights, preventing the landing gear down indicator light from illuminating. Consequently, he had to visually confirm that the landing gear was down. The pilot noted that both main landing gear were visible from the cockpit, and the nose landing gear could be seen via a mirror on the left sponson. Adjustments to the microswitches were made after those flights, but the pilot continued to conduct landings without the landing gear down indicator light illuminated.
Accident Flight Details
The pilot stated that for the accident flight, it was most likely that he switched the hydraulic pump off during the flight and did not notice the switch position or the indicated low hydraulic system pressure during the approach. Both the hydraulic switch position and checking hydraulic system pressure were part of his before-landing checklist, but he could not recall their position or indication during the accident approach.
Postaccident Functionality
After the accident, when the airplane was lifted, the right main landing gear was manually pushed into its down-and-locked position. The nose landing gear locked into position after activating the emergency gear extension pump. No evidence of preexisting malfunctions or failures that would have precluded normal operation was found.