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Casualties unknown

Forced Landing on Lake After Engine Partial Power Loss (N8220J)

West Milford, NJ, US

On June 27, 1993, a Piper PA-28-236 (registration N8220J) was involved in an aviation accident near West Milford, NJ. Investigators recorded the probable cause as: A manufacturer's defect which resulted in fatigue failure of the magneto impluse coupling spring and the loss of engine power. A factor was unsuitable terrain. 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

After takeoff, the engine experienced a partial power loss. The pilot executed a forced landing onto a lake, but the airplane struck a tree before coming to rest. Investigation revealed a broken impulse coupling spring causing engine timing retard.

Accident Sequence

After takeoff, the engine experienced a partial power loss. The pilot set up for a forced landing on a lake. Prior to landing, the airplane struck a tree, and then came to rest in the lake.

Post-Accident Investigation

Post-accident investigation found the two magnetos were driven by a single drive which had a broken impulse coupling spring. The broken spring allowed the engine timing to retard approximately 20 degrees. When the engine was run, it would not exceed 1900 RPM and it ran rough. When the impulse coupling was replaced, the engine produced 2800 RPM.

Metallurgical Examination

Metallurgical examination of the failed spring found the fracture originated with fatigue and then failed in overload. According to the NTSB metallurgical report, the cracks found at the origin of the failure were created when the spring was manufactured.

Engine failureStructural failure

Frequently asked questions

What happened in the 27 Jun 1993 Piper PA-28-236 accident near West Milford, NJ?

After takeoff, the engine experienced a partial power loss. The pilot executed a forced landing onto a lake, but the airplane struck a tree before coming to rest. Investigation revealed a broken impulse coupling spring causing engine timing retard.

What aircraft was involved and where did it happen?

The accident on 27 Jun 1993 involved a Piper PA-28-236, registration N8220J, at West Milford, NJ.

What was the probable cause of the accident?

A manufacturer's defect which resulted in fatigue failure of the magneto impluse coupling spring and the loss of engine power. A factor was unsuitable terrain.

More accident analyses

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001211X12709. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.