Casualties unknown

Pilot Reports Loss of Control and Collision with Dirt Berm During Jump Flight (N5123U)

Jamul, CA, US

On September 21, 1991, a Cessna 206 (registration N5123U) operated by Olen D. Mumma was involved in an aviation accident near Jamul, CA. Investigators recorded the probable cause as: THE PILOT'S FAILURE TO MAINTAIN DIRECTIONAL CONTROL DURING THE TAKEOFF GROUND RUN. CONTRIBUTING TO THE ACCIDENT WAS THE SOFT WET RUNWAY CONDITION. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 8 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

A pilot reported losing directional control and colliding with a dirt berm after taking off from a recently graded runway with soft sections and wet conditions.

Incident Overview

A pilot reported that an accident occurred during what he described as his fifth jump flight of the day. According to the pilot, the runway had recently been widened through grading, which left approximately half of the runway surface soft from the grading process. Additionally, the grading created a dirt berm of excess material along the left side of the runway.

Pilot Account

The pilot stated that during previous takeoffs, he experienced a slight pull to the right, which he managed by applying rudder input. He also noted that it had been raining and the ground was wet at the time of the flight. During the takeoff in question, the pilot lost directional control of the aircraft and subsequently collided with the dirt berm on the left side of the runway.

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Frequently asked questions

What happened in the 21 Sept 1991 Cessna 206 accident near Jamul, CA?

A pilot reported losing directional control and colliding with a dirt berm after taking off from a recently graded runway with soft sections and wet conditions.

What aircraft was involved and where did it happen?

The accident on 21 Sept 1991 involved a Cessna 206, registration N5123U, operated by Olen D. Mumma, at Jamul, CA.

What was the probable cause of the accident?

THE PILOT'S FAILURE TO MAINTAIN DIRECTIONAL CONTROL DURING THE TAKEOFF GROUND RUN. CONTRIBUTING TO THE ACCIDENT WAS THE SOFT WET RUNWAY CONDITION.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X18135. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.