Casualties unknown

Midair Collision of Two PA-36 Aircraft During Agricultural Spraying (N3634E)

Woonsocket, SD, US

On May 8, 1990, a Piper PA-36-375 (registration N3634E) was involved in an aviation accident near Woonsocket, SD. Investigators recorded the probable cause as: FAILURE OF THE PILOT OF N3634E TO FOLLOW THE BRIEFED PLAN OF OPERATION, AND FAILURE OF BOTH PILOTS TO SEE-AND-AVOID EACH OTHER (INADEQUATE VISUAL LOOKOUT). 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 2026-06-10Data APIEditorial standards

Two PA-36 agricultural aircraft collided while spraying adjacent fields after one pilot deviated from the prebriefed flight pattern. The collision occurred as both aircraft pulled up at the end of a swath run.

Incident Overview

Two PA-36 agricultural application aircraft, registered as N3634E and N6177A, were engaged in spraying operations over adjacent fields. The aircraft were owned and operated by a father-and-son team. Prior to the flight, the pilots had prebriefed to conduct spraying runs in an east/west direction. However, during the flight, the pilot of N3634E changed to north/south runs.

Collision Sequence

As both aircraft were pulling up at the end of a swath run, they converged and collided. The event involved two aircraft operating in close proximity, with one altering the agreed-upon flight path. No further details about the collision dynamics or post-impact events were provided in the source.

Operational Context

The agricultural spraying was taking place over fields that were adjacent to each other. The change in run direction by the pilot of N3634E occurred without coordination, leading to the convergence of the two aircraft. The collision happened as each aircraft completed its respective swath run and began to climb.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X23122. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.