NTSB Identification: IAD96LA064.
The docket is stored in the Docket Management System (DMS). Please contact Records Management Division
Accident occurred Friday, April 19, 1996 in DOVER, DE
Probable Cause Approval Date: 10/22/1996
Aircraft: Piper PA-22-135, registration: N3506A
Injuries: 2 Serious.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

The pilot stated that shortly after takeoff, as the airplane climbed through about 130 feet AGL, the engine lost power. He attempted to make an emergency landing in a nearby open field but struck a power line and nosed over, coming to rest inverted in the field. The pilot stated that the terrain surrounding the airfield contained obstacles and power lines. Postaccident examination of the engine revealed that the center main crankshaft bearing had spun. Examination of the mating surfaces around the bolt holes, and on both halves of the engine block center main bearing caps revealed evidence of fretting. The engine manufacturer stated that improper torque of the main bearing through bolts would result in fretting. Maintenance records indicate that the engine was overhauled in March 1989, and had accumulated 105 hours at its most recent annual inspection on 8/21/95.

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

the overhaul maintenance personnel's improper major overhaul procedure (improper torque on the engine block center through bolts), which resulted in an in flight loss of engine power. A related factor was the lack of suitable terrain available for a forced landing.

Full narrative available

Index for Apr1996 | Index of months