De Havilland U-6A N67207

Summary

On 24 September 1996 at about 18:15 local time, a De Havilland U-6A registered N67207, operated by U.s. Govt. Dept of Interior, was involved in an accident near King Salmon, Alaska, United States. 4 people were on board and 2 were seriously injured, 2 had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

24 September 1996 at 18:15

Classification

Accident

Location

King Salmon, Alaska, United States

Coordinates

58.7508, -156.5391

Aircraft

De Havilland U-6A

Registration

N67207

Category

Airplane

Engines

1

Operator

U.s. Govt. Dept of Interior

Operating rule

Part 91: General Aviation

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Brooks Camp → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ANC96TA163

2 people were seriously injured.

failure of the pilot to maintain sufficient airspeed during the initial climb after takeoff, which resulted in an inadvertent stall and collision with the terrain (water). Turbulence was a related factor.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The pilot and three passengers were departing a remote lake in a float equipped airplane. The pilot positioned the hydraulic actuated flaps to 20 degrees. After takeoff, about 150 ft above the water, the pilot positioned the flap lever to the 'UP' position in preparation of pumping the flaps up, but said he did not move the pump handle. Turbulence was present during the takeoff, and during a left turn, the pilot encountered a severe gust at the time he positioned the flap lever. The airplane stalled in a left turn that steepened to almost a 90 degree bank. The airplane descended and the left wing contacted the surface of the lake. The left wing was torn off the fuselage, and the floats were crushed upward. Both flaps are activated by a common torque tube connected to a double-acting flap actuating cylinder. At the accident scene, the right wing flap and right aileron were observed to be extended to an intermediate position. The weather conditions included 20 kts of wind, turbulence, and rain. The pilot expressed a concern that the flaps may have retracted without being pumped to the up position. An examination of the flap system and the ratchet valve assembly was conducted after the airplane was recovered and the wings were removed. Leakage of hydraulic fluid and air was observed through the ratchet valve. Additional testing of the ratchet valve at an overhaul facility did not reveal any leakage.

Quoted verbatim from the NTSB record.