Casualties unknown

Mid-Air Collision Between Ayres Thrush and Schweizer Ag Cat During Aerial Application Operations (N3633Q)

Marysville, CA, US

On May 9, 1991, an Ayres S2RT34 (registration N3633Q) operated by Bowles Flying Service was involved in an aviation accident near Marysville, CA. Investigators recorded the probable cause as: THE PILOTS' INADEQUATE VISUAL LOOKOUT FOR OTHER AIR TRAFFIC. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 2 related events involving the same aircraft type or operator are linked below.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-07-04Data APIEditorial standards

Two agricultural aircraft collided mid-air near an airstrip, resulting in both crashing into a field.

Accident Overview

Two agricultural aircraft were involved in a collision in flight. The pilot of an Ayres (Thrush) was conducting an aerial application flight over a field adjacent to an airstrip. A Schweizer (Ag Cat) had just departed from the same airstrip and was en route to perform an aerial application flight at another field.

Sequence of Events

As the Ayres pilot was beginning to reverse course to commence another application run, the Schweizer, which was on its initial climb, initiated a right turn. The flight paths of the two airplanes converged, resulting in a nearly head-on collision. After the collision, both airplanes descended out of control and crashed into the underlying field.

Conclusion

No probable cause was identified in the source. The collision occurred between two aircraft operating in proximity during aerial application activities.

Frequently asked questions

What happened in the 9 May 1991 Ayres S2RT34 accident near Marysville, CA?

Two agricultural aircraft collided mid-air near an airstrip, resulting in both crashing into a field.

What aircraft was involved and where did it happen?

The accident on 9 May 1991 involved an Ayres S2RT34, registration N3633Q, operated by Bowles Flying Service, at Marysville, CA.

What was the probable cause of the accident?

THE PILOTS' INADEQUATE VISUAL LOOKOUT FOR OTHER AIR TRAFFIC.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X17037. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.