On May 25, 1982, a Bell 47D1 (registration N6851) operated by Florida Flying Service Inc. was involved in an aviation accident near Jonesboro, AR. Investigators recorded the probable cause as: The pilot's inability to maintain a hover after takeoff from the loading truck, followed by the entanglement of the spray booms in the wheat field during the subsequent running landing, which resulted in the aircraft overturning. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A helicopter loaded with herbicide failed to sustain a hover after lifting off a truck, resulting in a running landing where spray booms became entangled in crops, causing the aircraft to overturn.
What happened
Following the loading of 40 gallons of herbicide onto the aircraft, the pilot initiated an attempt to lift off from the rear of the loading truck. The initial phase of the takeoff proceeded normally; however, as the helicopter cleared the vehicle, it became apparent that the aircraft could not sustain a hover in the prevailing conditions. Consequently, the pilot executed a running landing in an adjacent wheat field.
During this ground contact, the spray booms attached to the aircraft became entangled in the standing wheat crop. This entanglement caused the aircraft to nose down and roll over onto its back.
Probable cause
The pilot's inability to maintain a hover after takeoff from the loading truck, followed by the entanglement of the spray booms in the wheat field during the subsequent running landing, which resulted in the aircraft overturning.