Casualties unknown

Brake Failure During Touch-and-Go Practice Leads to Runway Excursion (N6951D)

Derby, KS, US

On October 5, 1983, a Piper PA-22-150 (registration N6951D) was involved in an aviation accident near Derby, KS. Investigators recorded the probable cause as: Improper seating of the left brake bleeder port O-ring, which allowed hydraulic fluid to leak with each brake application, resulting in an empty reservoir and brake failure. 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

During landing practice, the pilot experienced brake failure after the fifth landing. The aircraft continued off the runway, nose gear collapsed in a vegetation-covered ditch, and the aircraft nosed over.

Incident Overview

The pilot was practicing landings, stopping after each touchdown. After approximately the fifth landing, the brakes failed to operate, and the aircraft continued off the end of the runway. Before stopping, the nose gear entered a ditch and collapsed, causing the aircraft to nose over.

Pilot Statement

The pilot stated that he could not see the ditch before encountering it because it was covered with vegetation (grass).

Investigation Findings

An investigation revealed that the left brake bleeder port O-ring was improperly seated. This allowed hydraulic fluid to leak with each application of the brakes. The hydraulic reservoir was found to be empty.

Probable cause

Improper seating of the left brake bleeder port O-ring, which allowed hydraulic fluid to leak with each brake application, resulting in an empty reservoir and brake failure.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001214X44924. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.