What happened
Following takeoff, the pilot reported selecting the landing gear to the up position. He observed that the gear indicator lights showed one gear remained in the down position. The pilot cycled the gear mechanism and rechecked the indicator bulbs. Believing the gear was fully retracted after manually pumping the system, he proceeded with a water landing. Upon touchdown, the aircraft nosed over because the gear had not actually retracted.
The investigation
Examination of the aircraft revealed that the float plate was installed backwards. This mechanical error prevented the gear from locking in the up position despite the pilot's efforts to cycle and pump it. FAA inspectors interviewed four witnesses who confirmed that all landing gear appeared to be in the down position during the incident.
Findings
The primary issue involved the float plate being installed backwards, which caused the gear to remain down. The pilot relied on gear indicator lights that provided misleading information about the actual position of the landing gear. Additionally, the design allowed the left gear to be checked visually from the cockpit, but this visual check was not utilized or failed to reveal the mechanical fault before the landing attempt.