Incident Description
During preparations for landing, the pilot selected the 20-degree flap position. According to the pilot, the airplane immediately pitched nose-down into an almost vertical dive. Despite applying full aft elevator control, the pilot could not change the pitch attitude. The airplane subsequently impacted the water and sank to a depth of about 620 feet, where it was not recovered.
Pilot Statement
The pilot reported that the airplane had exhibited a tendency to pitch down on several prior occasions while he was flying it. He noted that this behavior had occurred previously, although no specific details regarding the circumstances or frequency were provided.
Other Pilot Experiences
In contrast to the pilot's account, the owner of the airplane and three other pilots who had flown it stated that the airplane operated normally. They reported no unusual pitch control issues during their flights.
Investigation Notes
No aircraft, engines, or components were recovered due to the depth of the water. The investigation did not establish a probable cause for the reported flight control anomaly.