On 15 Jul 2008, a Bell 47G-3B-1 operated by Slykerman Ag Aviation, Inc. was involved in an aviation accident near Shafter, CA. No fatalities were reported. Investigators recorded the probable cause as: The pilot failed to maintain sufficient altitude while maneuvering, compounded by the failure of the aircraft's ground illumination lights and the resulting impact on the pilot's ability to perceive the terrain. This summary draws on records from NTSB; 6 related events involving the same aircraft type or operator are linked below.
A helicopter sustained substantial damage after the pilot lost ground illumination lights while maneuvering low over an alfalfa field during a night spray mission.
What happened
During a nighttime agricultural spray flight over an alfalfa field, the pilot was descending and maneuvering close to the ground on a spray run. A few minutes after takeoff, the ground illumination lights within the helicopter ceased to function. Due to this loss of light, the pilot did not see the field before the aircraft's spray boom impacted the ground. The impact caused the helicopter to roll over, resulting in substantial damage to the aircraft. The pilot was not injured.
Findings
The failure of the helicopter's lights during the night flight.
The impact of the lighting failure on the pilot's visual perception.
The pilot's failure to maintain adequate altitude while maneuvering.
Probable cause
The pilot failed to maintain sufficient altitude while maneuvering, compounded by the failure of the aircraft's ground illumination lights and the resulting impact on the pilot's ability to perceive the terrain.
Contributing factors
Causes
Altitude — Not attained/maintainedLighting system — Failure