On May 6, 1990, a Bell UH-1B (registration N8142W) was involved in an aviation accident near Ulysses, KS. Investigators recorded the probable cause as: THE PILOT FAILED TO MAINTAIN PROPER ROTOR RPM, WHILE MANEUVERING OVER A HIGH OBSTRUCTION (POWER LINE) AT THE END OF A SWATH RUN, WHICH RESULTED IN AN INADVERTENT DESCENT & COLLISION WITH THE TERRAIN. THE HIGH OBSTRUCTION WAS CONSIDERED TO BE A RELATED FACTOR. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
After completing a second swath run, a helicopter maneuvered over power lines, entered a descent, and crashed. No preimpact mechanical problems were found. The owner estimated the aircraft carried 1,983 lbs of spray and 900 lbs of fuel.
Incident Overview
A helicopter engaged in aerial application operations crashed after clearing a set of power lines at the eastern boundary of a field. The pilot had refueled and loaded the aircraft with a spray mixture before proceeding to the work site.
Flight Sequence
The pilot initiated aerial application and completed the second swath run. Subsequently, he maneuvered the helicopter upward and over 'big' power lines located on the east end of the field. Around that time, the helicopter began a descent and subsequently crashed.
Investigation Findings
Investigators examined the wreckage and found no evidence of a preimpact mechanical malfunction. The owner provided estimates that the helicopter was carrying approximately 1,983 pounds of spray material and 900 pounds of fuel at the time of the accident.