Casualties unknown

1998-01-24: Lake LA-4-200 (N2994P) — Sarasota, FL

Sarasota, FL, US

On January 24, 1998, a Lake LA-4-200 (registration N2994P) was involved in an aviation accident near Sarasota, FL. Investigators recorded the probable cause as: 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. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

During initial climb after a touch-and-go landing on a lake, the aircraft shuddered and pitched nose down. The pilot performed an emergency water landing after freeing the elevator control. Postaccident examination revealed fatigue failure from fretting wear on the left horizontal stabilizer attachment.

Accident Sequence

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 Examination

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.

Airworthiness Directive

An airworthiness 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.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001211X09489. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.