NTSB Identification: CHI82FA123
14 CFR Part 91: General Aviation
Accident occurred Friday, April 16, 1982 in BIRD ISLAND, MN
Probable Cause Approval Date: 04/16/1983
Aircraft: MOONEY M20J, registration: N3201P
Injuries: 3 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 AIRCRAFT DEPARTED THIEF RIVERS, MN AND PROCEEDED EN ROUTE TO NEW ULM, MN. ONE WITNESS NEAR THE ACCIDENT SITE HEARD A NOISE THAT SOUNDED TO HIM LIKE AN EXPLOSION. HE AND OTHER WITNESSES IN THE VICINITY SAW THE AIRCRAFT DESCENDING OUT OF CONTROL IN A ROLL OR A SPIN BEFORE IT CRASHED. ALSO, THEY SAW TWO OBJECTS FALLING FROM THE AIRCRAFT, ONE SMALL AND ONE LARGE. AN INVESTIGATION REVEALED THAT A PROPELLER BLADE, AND THEN THE ENGINE, HAD SEPARATED IN FLIGHT. THE PROPELLER BLADE WAS FOUND ABOUT TWO WEEKS LATER APPROXIMATELY 1/4 MILE LEFT OF THE FLIGHT PATH. AN EXAMINATION REVEALED THAT THE PROPELLER BLADE HAD FAILED FROM FATIGUE CRACKING. THE FATIGUE ORIGINATED FROM A 1/16 INCH DEEP FORGING FOLD IN THE SURFACE OF THE BLADE NEAR THE BUTT END. THE PROPELLER, A MCCAULEY MODEL 90DHB-16E, HAD 340 HRS TOTAL FLIGHT TIME.

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

PROPELLER SYSTEM/ACCESSORIES,BLADE..FATIGUE

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

INADEQUATE QUALITY CONTROL..MANUFACTURER


Contributing Factors

PROPELLER SYSTEM/ACCESSORIES,BLADE..SEPARATION


Contributing Factors

ENGINE ASSEMBLY..VIBRATION


Contributing Factors

ENGINE ASSEMBLY..SEPARATION

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