Casualties unknown

1987-04-28: Piper PA-25 (N6749Z) — Robert S. Otterson — Valley City, ND

Valley City, ND, US

On April 28, 1987, a Piper PA-25 (registration N6749Z) operated by Robert S. Otterson was involved in an aviation accident near Valley City, ND. Investigators recorded the probable cause as: The pilot's failure to maintain control during takeoff from a gravel road while operating an agricultural aircraft loaded with water in its hoppers. 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 1781061362Data APIEditorial standards

A commercial pilot testing an agricultural aircraft for lease lost control during takeoff from a gravel road, causing the plane to bounce across intersecting roads and come to rest in a field.

What happened

A commercial pilot was conducting a pre-lease evaluation of an agricultural aircraft. The intended flight plan involved taking off from a stretch of gravel road rather than a paved runway. During the ground run, the aircraft became airborne but failed to gain sufficient altitude or distance. It touched down in a field adjacent to the road, bounced across an intersecting roadway, and finally came to rest in another nearby field.

The investigation

Investigators examined the wreckage and the loading configuration of the aircraft. They noted that the aircraft was loaded with water in its spray hoppers at the time of the accident. This specific loading condition meant that no hazardous materials (HazMat) were released or spilled during the incident, despite the structural damage sustained by the airframe.

Findings

The primary factors contributing to the accident included the choice of takeoff surface and the aircraft's performance characteristics under load. The use of a gravel road for takeoff presented significant challenges for an agricultural aircraft, particularly when carrying heavy loads such as water in its hoppers. The bounce across the intersecting road indicates a loss of control or insufficient lift during the critical phase of flight immediately after initial rotation.

The pilot was operating an agricultural aircraft during a test flight. The incident resulted in significant damage to the airframe, though no injuries were reported among the crew or on the ground. The presence of water in the hoppers mitigated environmental hazards but likely impacted the aircraft's weight and balance, contributing to the inability to clear the takeoff path safely.

Safety message

This incident highlights the risks associated with non-standard takeoff operations for agricultural aircraft. Operators must carefully evaluate the suitability of alternative takeoff surfaces, such as gravel roads, especially when the aircraft is loaded with heavy payloads like water. Proper performance calculations and awareness of ground effect limitations are critical to ensuring safe clearance during takeoff from unprepared surfaces.

Probable cause

The pilot's failure to maintain control during takeoff from a gravel road while operating an agricultural aircraft loaded with water in its hoppers.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001213X30663. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.