The aircraft, which was equipped with floats and retractable landing gear units, was on its second flight after major maintenance. During the flight the engine suffered rough running, prompting the pilot to declare a PAN and expedite a landing. After selecting the gear down, he and his passenger checked the mechanical gear indicator ‘flags’ to confirm that the gear was down. The pilot could not recall if all the green gear down and locked indicator lights were illuminated.
After a smooth touchdown the aircraft rolled normally for 40 to 50 m, before veering to the left, coming to a stop on the shoulder of Runway 12. It transpired that the left landing gear had collapsed, causing the left float to contact the runway. On lifting the aircraft, the left main gear extended and locked down.
Subsequent retraction tests did not reveal any problems with the landing gear. Examination of the engine revealed significant fouling of one spark plug. 8 hours flying have since been completed without any landing gear problems.
The pilot considered that the PAN condition may have been contributory as there was no opportunity to go around or double-check the gear, the priority being to land.
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Published 14 September 2017