Diehl INTERSTATE S-4 N4BZ

Summary

On 11 September 1999 at about 19:45 local time, a Diehl INTERSTATE S-4 registered N4BZ was involved in an accident near Anchorage, Alaska, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

11 September 1999 at 19:45

Classification

Accident

Location

Anchorage, Alaska, United States

Nearest airport

Sand Lake

Coordinates

61.1605, -149.9900

Aircraft

Diehl INTERSTATE S-4

Registration

N4BZ

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Unknown → Butterfly Lake

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ANC99LA143

Nobody was injured.

The pilot's inadequate planning/decision, and his failure to maintain directional control of the airplane. Factors in the accident were a short runway/lake area for departure, and the pilot's extension of the landing gear steering system (water rudders) during the takeoff run.

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

Read the full NTSB narrative

The pilot was taking off from a private lake in a homebuilt/experimental float equipped airplane. While waiting for a departure clearance, he was taxiing in a tight left turn in a cove located at the west end of the lake. The water rudders were extended and displaced to the left. The pilot said the water rudders are stiff when they are deployed. After receiving his clearance, he began his departure from the cove. During the takeoff run, he left the water rudders extended. When the airplane became airborne, he said the airplane continued to turn left. He was unable to prevent the airplane from colliding with a small boat dock, and the top of a small boat. The airplane then collided with trees along the edge of the lake. An FAA inspector said the distance from the cove used for departure to the dock was about 500 feet. The distance from the dock to the trees was about 100 feet. In the Pilot/Operator report (NTSB form 6120.1/2) submitted by the pilot, he stated, in part: '...At rotation, could not control P-Factor of engine with max right rudder.' The pilot also indicated there was no mechanical malfunction/failure.

Quoted verbatim from the NTSB record.