Casualties unknown

1999-08-02: Air Tractor AT-401 (N15585) — Moore Haven, FL

Moore Haven, FL, US

On August 2, 1999, an Air Tractor AT-401 (registration N15585) was involved in an aviation accident near Moore Haven, FL. Investigators recorded the probable cause as: The pilot's failure to ensure adequate airspeed during takeoff in high-temperature conditions, which resulted in an inadequate climb performance and collision with brush. 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

An agricultural aircraft failed to accelerate adequately during takeoff in extreme heat, prompting the pilot to dump its chemical load before lifting off and striking brush at the end of the runway.

What happened

The incident occurred during a crop dusting operation under severe weather conditions. The ambient temperature was recorded at 103 degrees Fahrenheit, creating high-density altitude conditions that significantly degraded aircraft performance. As the pilot began the takeoff roll, it became apparent that the aircraft was not accelerating at the expected rate for a safe departure.

Recognizing the insufficient airspeed and runway remaining, the pilot made the decision to jettison the chemical load to reduce weight. Despite this action, the aircraft barely achieved lift-off speed. It climbed just enough to clear the immediate threshold but immediately collided with brush located at the end of the runway. The impact caused the aircraft to lose control, leading it to settle into a second area of brush nearby where it finally came to rest.

The investigation

Following the accident, the pilot provided a statement regarding the condition of the airframe and systems. He reported that there were no mechanical difficulties with the aircraft prior to or during the takeoff attempt. This indicates that the failure to achieve adequate performance was likely due to environmental factors rather than equipment malfunction.

Findings

The primary factor in this accident was the high temperature of 103 degrees F, which reduced air density and engine efficiency. The resulting inadequate acceleration prevented the aircraft from gaining sufficient speed to clear obstacles at the end of the runway. The pilot's decision to dump the load was a correct response to the emergency, but it occurred too late to prevent the collision with the brush.

Probable cause

The pilot's failure to ensure adequate airspeed during takeoff in high-temperature conditions, which resulted in an inadequate climb performance and collision with brush.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X19584. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.