NTSB Identification: MIA98LA078.
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Accident occurred Saturday, January 24, 1998 in SARASOTA, FL
Probable Cause Approval Date: 12/31/1998
Aircraft: Lake LA-4-200, registration: N2994P
Injuries: 2 Uninjured.
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 had just completed a touch-and-go landing on a lake. During the initial climb at an altitude of less than 500 feet, the airplane shuddered, then pitched nose down. The pilot reduced power and pulled the control column with negative results, then forcibly pushed and pulled the control column, which freed the elevator control. He maneuvered the airplane for an emergency water landing. Postaccident visual examination of the airplane revealed that the left horizontal stabilizer was displaced down about 12 degrees from the normally installed position. Further examination revealed that an attachment ear for the left horizontal stabilizer fitting beam had failed due to fatigue in an area of fretting wear. Fretting wear was also detected on the adjacent angle/top beam. For comparison, the right fitting/beam and angle/top beam were removed and examined. Fretting wear was detected on both components. A small crack was also detected on an attachment for the right fitting/beam, which had originated from fretting wear associated from the respective angle/top beam. An air worthiness directive (AD 98-10-12), effective 6/8/98, was issued to inspect the affected aircraft, to ensure proper clearance, and to correct if fretting, cracking, or corrosion were found.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: inadequate clearance and fretting wear of the fitting/beam attachment to the angle/top beam, due to inadequate design, which resulted in fatigue and subsequent failure of the fitting/beam attachment ear. Full narrative available
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