Casualties unknown

Post-Takeoff Downdraft Results in Collision with Terrain (N56687)

Kennebec, SD, US

On August 8, 1984, a Piper PA-36-285 (registration N56687) was involved in an aviation accident near Kennebec, SD. 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

An aircraft collided with the ground after encountering a downdraft at 25 feet altitude shortly after takeoff. The pilot reported the descent could not be arrested. The aircraft was operated 400 pounds below maximum takeoff weight.

Incident Overview

Shortly after takeoff, while the aircraft was at an altitude of 25 feet, it encountered a downdraft near a small hill at the end of the runway. The descent caused by the downdraft could not be arrested, and the aircraft subsequently collided with the ground.

Pilot Account

According to the pilot, the wind was reported from the west at 5 to 7 knots, which constituted a headwind. The pilot also stated that the aircraft was being operated 400 pounds below its maximum takeoff weight. The density altitude at the time was approximately 3,800 feet.

Aircraft and Operational Details

The pilot did not have knowledge of the accident aircraft's maximum gross weight, which was 3,900 pounds. Instead, the pilot believed the maximum gross weight to be 4,400 pounds, a figure correct for another agricultural aircraft that the pilot had occasionally used.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001214X40679. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.