Casualties unknown

1986-07-17: Beech D18S (N76Q) — Ft. Lauderdale, FL

Ft. Lauderdale, FL, US

On July 17, 1986, a Beech D18S (registration N76Q) was involved in an aviation accident near Ft. Lauderdale, FL. Investigators recorded the probable cause as: The bolt attaching the upper end of the drag leg failed in fatigue. 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 the landing roll, the right main landing gear collapsed after the bolt attaching the upper end of the drag leg failed in fatigue. Company maintenance personnel did not regularly remove this bolt for inspection, although the aircraft was not subject to the relevant service instruction due to its drag leg configuration.

Event Description

During the landing roll, the right main landing gear collapsed. The collapse occurred when the bolt that attaches the upper end of the drag leg failed in fatigue.

Landing Gear Failure

The aircraft was equipped with a drag leg that used a bolt to connect its upper end to the structure. That bolt experienced fatigue failure, leading to the separation of the drag leg and subsequent collapse of the landing gear.

Maintenance Practices

Company maintenance personnel did not remove this bolt regularly for inspection. Regular inspection of the bolt might have detected fatigue cracking before the failure.

Applicability of Service Instruction

Beech Aircraft Service Instruction 1183 calls for inspecting this bolt on aircraft equipped with certain part number drag legs. However, this aircraft was not affected by the instruction due to the specific drag leg installed. The drag leg on this aircraft was of a different part number than those covered by the service instruction.

Conclusion

The investigation determined that the bolt failed in fatigue, leading to the landing gear collapse. No other causal factors were identified.

Probable cause

The bolt attaching the upper end of the drag leg failed in fatigue.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001213X34243. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.