Casualties unknown

Loss of directional control during rollout after tailwheel installation (N3170Z)

Palo Alto, CA, US

On December 1, 1991, a Piper PA22-150 (registration N3170Z) operated by James Ham was involved in an aviation accident near Palo Alto, CA. Investigators recorded the probable cause as: The pilot's failure to maintain directional control during the landing rollout after modifying the aircraft with a tail wheel assembly. 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

A pilot lost directional control and ground looped a modified aircraft upon landing on runway 12, despite having 600 hours of taildragger experience.

What happened

The pilot reported that the accident occurred following the recent modification of his aircraft, specifically the installation of a tail wheel assembly. After touching down on runway 12, the pilot attempted to maintain control during the rollout phase. However, he lost directional control of the aircraft shortly after landing. The loss of control resulted in the airplane ground looping.

At the time of the incident, the wind conditions were calm, with a wind direction from 120 degrees at a speed of 5 knots. The pilot noted that he had accumulated 600 hours of flight time specifically in taildragger aircraft prior to this event.

The investigation

A post-accident examination of the airplane was conducted to determine the mechanical status of the aircraft. Inspectors found no evidence of any pre-existing mechanical malfunctions or failures that could have contributed to the loss of control.

Probable cause

The pilot's failure to maintain directional control during the landing rollout after modifying the aircraft with a tail wheel assembly.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X18615. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.