Stinson 108-1 N97946

Summary

On 23 October 2008 at about 05:05 local time, a Stinson 108-1 registered N97946 was involved in an accident near Concrete, Washington, United States. 3 people were on board and one died, 2 were seriously injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

23 October 2008 at 05:05

Classification

Accident

Location

Concrete, Washington, United States

Nearest airport

Concrete Municipal (3W5)

Coordinates

48.5322, -121.8719

Aircraft

Stinson 108-1

Registration

N97946

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Concrete → Auburn

Aircraft damage

Substantial

Weather

VMC

Light

Night/Dark

NTSB number

WPR09LA022

1 person died.

The loss of engine power during initial climb due to the pilot's improper exhaust system maintenance, which resulted in restriction of the carburetor's air intake.

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

Read the full NTSB narrative

For 7 years, the pilot had performed maintenance, which included 100-hour and annual inspections of his airplane's engine. On an undetermined date, a rope-like material had been placed between the exhaust's heater shroud and muffler. At an undetermined date/time, this material became separated from its installed location. During takeoff on the accident flight, the rope-like material became lodged in the carburetor's air intake. This resulted in restricting the flow of air into the carburetor, and the engine lost power. It was a dark night, and the airplane collided with trees during the ensuing forced landing. Toxicology results were consistent with the relatively recent use of diphenhydramine, an over-the-counter antihistamine with sedative and impairing effects, and propoxyphene, a prescription narcotic medication with impairing effects. The levels detected on toxicology evaluation were not consistent with impairment at the time of the accident. The pilot had indicated to the FAA a history of diabetes and kidney stones, but not the use of diphenhydramine or propoxyphene, and it could not be determined whether medical conditions or the use of medication may have played a role in his decision to insert the rope-like material in the engine compartment.

Quoted verbatim from the NTSB record.