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Casualties unknown

Engine Crankshaft Failure Forces Landing and Gear Collapse (N48DL)

Alamosa, CO, US

On April 3, 1989, a Piper PA-28RT-201T (registration N48DL) operated by Lyons, Dean P. was involved in an aviation accident near Alamosa, CO. Investigators recorded the probable cause as: Engine crankshaft failed at #2 and #3 journals; the #2 pin failed from fatigue, and the #3 pin failed from overload. 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 2026-07-04Data APIEditorial standards

During flight at 16,000 ft, an engine lost power and vibrated. The pilot attempted a forced landing at Alamosa Airport but landed in a field, encountering irrigation ditches. Post-crash examination revealed crankshaft failure due to fatigue and overload.

Incident Summary

While cruising at an altitude of 16,000 feet, the aircraft's engine experienced a sudden loss of power accompanied by noticeable vibration. The pilot immediately contacted Air Route Traffic Control Center (ARTCC) and declared an intention to perform a forced landing at Alamosa Airport. However, the aircraft was unable to reach the airport, and the pilot instead selected a field approximately one mile away for the landing.

Landing and Damage

During the landing in the field, the aircraft encountered several irrigation ditches. The landing gear subsequently collapsed as a result of the impact. The extent of damage to the airframe and components apart from the gear collapse was not specified in the report.

Examination Findings

A post-incident examination of the engine revealed that the crankshaft had failed at the number 2 and number 3 journals. There was evidence indicating that the number 2 pin had failed due to fatigue, after which the number 3 pin failed due to overload. No other contributing factors were identified in the examination.

Probable cause

Engine crankshaft failed at #2 and #3 journals; the #2 pin failed from fatigue, and the #3 pin failed from overload.
Engine failureStructural failure

Frequently asked questions

What happened in the 3 Apr 1989 Piper PA-28RT-201T accident near Alamosa, CO?

During flight at 16,000 ft, an engine lost power and vibrated. The pilot attempted a forced landing at Alamosa Airport but landed in a field, encountering irrigation ditches. Post-crash examination revealed crankshaft failure due to fatigue and overload.

What aircraft was involved and where did it happen?

The accident on 3 Apr 1989 involved a Piper PA-28RT-201T, registration N48DL, operated by Lyons, Dean P., at Alamosa, CO.

What was the probable cause of the accident?

Engine crankshaft failed at #2 and #3 journals; the #2 pin failed from fatigue, and the #3 pin failed from overload.

More accident analyses

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001213X28074. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.