Williamson/Williamson RV-4 N6NW

Summary

On 7 July 1999 at about 23:00 local time, a Williamson/Williamson RV-4 registered N6NW was involved in an accident near Coos Bay, Oregon, United States. One person was on board and one was seriously injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

7 July 1999 at 23:00

Classification

Accident

Location

Coos Bay, Oregon, United States

Coordinates

43.3701, -124.1402

Aircraft

Williamson/Williamson RV-4

Registration

N6NW

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

North Bend → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

SEA99LA108

1 person was seriously injured.

Inadequate aircraft preflight inspection (engine air inlet cover not removed) by the pilot, resulting in obstruction of the carburetor air inlet in flight and consequent inflight engine stoppage. Factors contributing to the accident included a vehicle entering the attempted forced landing surface, and fence posts in the forced landing area.

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

Read the full NTSB narrative

The pilot reported that after takeoff, at an altitude of approximately 600 feet above ground level (AGL), the engine suddenly stopped. Attempts to restart the engine were unsuccessful, and the pilot attempted a forced landing onto a road. As the aircraft approached the road at about 300 feet AGL, a car turned onto the road. It became apparent to the pilot that the aircraft would overtake and hit the car from the rear if he attempted to land on the road, and the pilot thus attempted to turn the airplane to go up a driveway off the road. The airplane subsequently struck fence posts during the forced landing. FAA inspectors who performed a post-accident examination of the aircraft's engine found a 2 1/2 inch diameter soft blue ball, wrapped in Scotch tape and with a flag of red plastic tape attached, lodged in the carburetor air inlet. The inspectors reported that the aircraft owner identified the ball as an improvised engine air inlet cover, which he had placed into the engine air inlet to prevent foreign objects from entering the inlet during ground storage of the aircraft. The FAA inspectors reported finding no other evidence of pre-impact engine mechanical malfunction.

Quoted verbatim from the NTSB record.