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NTSB Report
August 5, 2020 · Hughes 369 D · N104SU
Delia, KS
Overview
Report Status
Probable Cause
Event Type
Accident
Date
August 5, 2020
Injury Outcomes
No injuries (1 uninjured)
Location
Delia, KS
Aircraft
Hughes 369 D (1977)
Tail Number
N104SU
Operator
Signature Utility
Injuries
None
Aircraft Damage
Substantial
NTSB Number
CEN20CA334
While conducting an aerial tree-trimming flight with an external load aerial saw, the pilot heard a loud “thump” and felt a collision. A heavy vibration was felt, and the pilot landed in a nearby cornfield without further incident. Upon landing substantial damage was found to the main rotor blades with embedded pieces of tree bark and vegetation found in the blades. The pilot reported that there were no mechanical malfunctions that contributed to the accident. The aerial saw was suspended about 120 ft below the helicopter. The operator noted that this distance is normally adequate to prevent foreign object damage (FOD) to the main rotor blades.
NTSB Probable Cause
Environmental issues-Physical environment-Object/animal/substance-Debris/dirt/foreign object-Effect on equipment - C
Full Narrative
While conducting an aerial tree-trimming flight with an external load aerial saw, the pilot heard a loud “thump” and felt a collision. A heavy vibration was felt, and the pilot landed in a nearby cornfield without further incident. Upon landing substantial damage was found to the main rotor blades with embedded pieces of tree bark and vegetation found in the blades. The pilot reported that there were no mechanical malfunctions that contributed to the accident. The aerial saw was suspended about 120 ft below the helicopter. The operator noted that this distance is normally adequate to prevent foreign object damage (FOD) to the main rotor blades.
Flight
Event TypeAccident
Event Time17:45 CDT
Nearest Airport0nm
Flight Plan FiledNone
Flight Plan ActivatedNo
Aircraft FireNo
Aircraft ExplosionNo
Aircraft
AircraftHughes 369 D
Tail NumberN104SU
Aircraft CategoryHeli
DamageSubstantial
OperatorSignature Utility
Operating RulePart 133
Engines1
Engine TypeTurboshaft
Engine DetailsRolls-Royce · 250-C20B · Turboshaft · 420
Seats2
People & Injuries
Injury SummaryNo injuries (1 uninjured)
Fatal0
Serious0
Minor0
Uninjured1
Total1
Crew 1Age 39 · Second Class · None
Conditions
ConditionsVMC
LightDaylight
Wind120° @ 8 kt
Visibility10 sm
CeilingNone
Temperature / Dew Point59
Altimeter29.98 inHg
Observation Time22:53
Weather SourceWFAC