ANC99FA070 · Cessna A185F

The private pilot was landing the float equipped airplane on choppy water with a left-quartering headwind of 10 knots. The airplane landed hard on the left float, bounced into the air, and landed on the right float. The right wing contacted the water, and the airplane nosed over, coming to rest with the left wing submerged and the right wing pointed into the air. The three passengers on board released their seatbelts, and exited the right cabin door. Both the pilot and the right-front seat passenger were unable to locate, release, or cut the pilot's seatbelt. The pilot was described by one passenger as 'awake, and alert, and fully cognizant of the situation; able to cooperate but unable to complete the task for whatever reason.' The airplane slowly rolled inverted and remained afloat. The passengers, and a rescuer from shore, were unable to open the pilot's locked door, or remain submerged in the 40 degree Fahrenheit water. The diver who removed the pilot told the NTSB investigator-in-charge that when he released the pilot's seatbelt, the pilot was removed without difficulty. Postaccident inspection by the IIC revealed that once unlocked, the door could be opened normally. Reaching the pilot's door handle required the occupant to twist his torso to the left, and reach behind his shoulder. The pilot's seatbelt release buckle could be opened with one hand and less than 10 pounds of force. The pilot's buckle was located aft of his left hip, and sandwiched between the left door and the seat. With the door closed, the seatbelt buckle was masked under the door armrest. The Cessna inertial reel, seatbelt/shoulder harness assembly was installed according to the manufacturer's specifications. FAA Advisory Circular AC-21-34 states in part: 'A proper installation geometry for the diagonal shoulder harness positions the shoulder belt so that it passes over the midpoint of the shoulder, with the lower end fastened well to the side of the occupant's hip.' Toxicology tests revealed the presence of phentermine, a prescription stimulant, similar to amphetamines, was present in the pilot's blood and urine. No record of a prescription was found. The pilot was a pharmacist. The Physician's Desk Reference contains the following contraindications regarding phentermine: '...agitated states...phentermine hydrochloride may impair the ability of the patient to engage in potentially hazardous activities such as operating a motor vehicle; ...Caution is to be exercised in prescribing...for patients with even mild hypertension.'

Verbatim NTSB analysis and probable cause from the NTSB dataset