HISTORY OF FLIGHT
On August 20, 2008, about 0915 Pacific daylight time, a float-equipped Cessna TU206G, N818CT, nosed over after touchdown on Cherry Lake near Groveland, California. The pilot/owner operated the airplane under the provisions of 14 Code of Federal Regulations Part 91. The pilot and three passengers received minor injuries. The airplane sustained substantial damage to the left wing. Visual meteorological conditions prevailed for the local area flight that departed the Columbia Airport (O22), Columbia, California, about 0845. No flight plan had been filed for the flight destined for Cherry Lake.
In the pilot's written statement, the flight from O22 to Cherry Lake was uneventful. Upon arrival at Cherry Lake, he noted rising terrain and no wind. He set up for a standard approach, reduced his airspeed to 90 knots, and input 10 degrees of flaps. He checked that the landing gear lever was in the up position, and stated that they were headed into the sun. On the base leg, he reduced his speed an additional 20 knots and input 30 degrees of flaps. The pilot stated that in "the black glass water lost depth perception," and stopped the decent to head for the shoreline to set up for a "glass water landing." He further reduced his airspeed another 35 knots and identified the shoreline to set up for another landing. About 25 feet above ground level (agl), and 60 knots, he applied the "'three P's' pitch-power-patience, procedure for a glass water landing." On touchdown, the airplane "skipped" to the right, and the pilot corrected back to the left. The pilot stated that the airplane "flipped and sank inverted…."
The pilot reported to the Federal Aviation Administration (FAA) that he made a glassy water approach (power on and minimum sink rate) on a westerly heading. Upon touchdown, the nose went down, and the airplane became inverted. The pilot stated that he retracted the landing gear after takeoff, and verified it was retracted (using position lights in the cockpit) prior to the accident landing.
Responding rescue personnel noted that the airplane was upside down in the water about 2 miles from the shoreline.
According to recovery personnel the flaps noted in the full down position, the landing gear was in the down position, and the circuit breakers for the landing gear system and the landing gear advisory system were in the OPEN positions. The landing gear handle was in the UP position.
TESTS AND RESEARCH
The airplane was equipped with the Wipline 3730 amphibious floats; an electrical/hydraulic actuation system manufactured by Wipaire, St. Paul, Minnesota. The system is equipped with an airspeed actuated landing gear advisory system with an aural warning alarm. In order to facilitate an examination of the system, Wipaire was contacted for the landing gear electrical schematics along with assistance in troubleshooting the landing gear. According to the FAA, the warning systems, along with other cues, should have provided the pilot with ample opportunity to determine that a water landing was not advisable.
Wipaire provided a list of items to look for during the examination: 1. Check electrical system for power to pump motor as well as looking for broken or loose wires 2. Check all indicator lights UP and DOWN 3. Check solenoid and pressure switch 4. Bypass and run electric motor 5. Check hydraulic fluid level 6. Check screen in reservoir
All of the items were checked under the auspices of the FAA inspector, with no anomalies noted. The landing gear system should have functioned normally in either the retracted or extended positions.