This October 2008 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Aircraft: Stinson 108-1. Injuries: 1 Fatal, 2 Serious. Location: Concrete, Wash. Aircraft damage: Destroyed.
What reportedly happened: The pilot was a 71-year-old retired airline captain. According to the pilot’s last application for an aviation medical certificate made in December 2007 his total flight time was 34,100 hours. He also held an FAA airframe and powerplant mechanic certificate. The airplane’s logbooks indicated that between 2001 and 2008, the pilot performed maintenance as well as the required inspections for his airplane.
The accident occurred during a night takeoff. The passenger who occupied the front right seat stated that seconds prior to the crash, the pilot stated that the airplane was losing power. The airplane collided with trees and then the ground.
The post-crash investigation found rope-like material lodged in the carburetor’s air intake. This resulted in restriction of the flow of air into the carburetor, which resulted in a loss of engine power. Investigators determined that on an undetermined date, a rope-like material had been placed between the exhaust’s heater shroud and muffler, and subsequently this material became separated from its installed location.
Probable cause: 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.
For more information: NTSB.gov