On April 4, 1993, a Lake LA-4-200 (registration N39375) operated by Helgeson, Robert C. was involved in an aviation accident near Gold Bar, WA. Investigators recorded the probable cause as: THE PILOT'S FAILURE TO MAINTAIN ADEQUATE AIRSPEED WHILE MANEUVERING FOR A WATER LANDING. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
An airplane was discovered submerged in 40 feet of water near the northeast end of Lake Isabel, with impact damage indicating a near-vertical, nose-down collision. The pilot had been instructed to circle the lake before landing.
Incident Overview
An airplane was found submerged in approximately 40 feet of water, about 40 feet from the shoreline at the northeast end of Lake Isabel. The wreckage showed impact damage consistent with a near-vertical, nose-down attitude at the time of collision.
Environmental Context
Lake Isabel is surrounded by rapidly rising mountainous terrain on all sides. At its northeast end, the lake narrows to a width of roughly 530 feet.
Pilot Training Background
The pilot's flight instructor stated that the pilot had been taught to circle the lake a few times before landing to assess water conditions. This procedure is intended to evaluate the surface state prior to a water landing.