NTSB Identification: SEA83FA018
14 CFR Part 91: General Aviation
Accident occurred Saturday, November 13, 1982 in LYNNWOOD, WA
Probable Cause Approval Date: 11/13/1983
Aircraft: STINSON 108-3, registration: N6943M
Injuries: 2 Fatal.

NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.

THE ENG FAILED APPROACHING THE ARPT AT LOW ALTITUDE. THE ACFT STRUCK TREES DURING A DESCENDING TURN TOWARD A POWER COMPANY RIGHT-OF-WAY. INVESTIGATION REVEALED THAT THE IMPULSE DRIVE SPRINGS ON BOTH MAGNETOS HAD FAILED IN FATIGUE. THE SPRINGS ARE NOT ASSIGNED A SERVICE LIFE LIMIT. REJECTION CRITERIA DURING MAGNETO OVERHAUL PERTAINS TO DISTORTION OF COIL SYMMETRY & OBVIOUS SIGNS OF WEAR. NO RECORD COULD BE FOUND OF REPLACEMENT OF THE MAGNETO IMPULSE SPRINGS. IT IS POSSIBLE THAT THEY WERE ORIGINAL EQUIPMENT DATING TO 1948.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

IGNITION SYSTEM,MAGNETO..FATIGUE

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

IGNITION SYSTEM,MAGNETO..FAILURE,TOTAL


Contributing Factors

OBJECT..TREE(S)

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