ERA24LA267

NTSB accident investigation · Garlick Helicopters OH-58A+ · Cisco, GA · June 18, 2024

Accident · Minor injuriesClass 3 · LimitedFinal report
Date
June 18, 2024, 13:30 local (17:30 UTC)
Place
Cisco, GA
Injuries
1 minor
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N72BMGarlick Helicopters OH-58A+
Defining event
Maneuvering-low-alt flying: Unknown or undetermined
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Eastern Region Aviation
Parties
FAA/FSDO, Rolls Royce
FAA report
20240618021919A
Case key
194502

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

On this page

Probable cause

A reported total loss of engine power for reasons that could not be determined.

Findings · 2

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Not determinedNot determined › Not determined · Unknown/Not determinedGarlick Helicopters OH-58A+: 1 caseAll aircraft: 2,247 casesProbable cause
Power plantAircraft › Aircraft power plant · Unknown/Not determinedGarlick Helicopters OH-58A+: 1 caseAll aircraft: 198 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

The pilot of the helicopter was performing an aerial application flight. He reported that, while taking off after loading chemical for the third application flight of the day, the helicopter felt “heavy,” but all the engine instruments were in the normal operating range, so he continued the flight. During the first teardrop turn back to the field, the engine rpm dropped and he saw that the red “engine out” light was illuminated. The pilot immediately looked for a place to land and tried to land between two trees. The helicopter contacted the trees and rolled over, coming to rest inverted and resulting in substantial damage to the main rotor blades and tail rotor assembly. Examination of the engine and a successful engine test run did not reveal any anomalies that would have precluded normal operation. Based on the available information, the reason for the loss of engine power could not be determined.

Factual narrative

On June 18, 2024, about 1330 eastern daylight time, a Garlick Helicopters Inc, OH-58A+, N72BM, was substantially damaged when it was involved in an accident near Cisco, Georgia. The pilot sustained minor injuries. The helicopter was operated as a Title 14 Code of Federal Regulations Part 137 aerial application flight. According to the pilot, he departed from Greensboro, Georgia, at 1043 to spray a field in Cisco, Georgia. After the 1.15-hour flight to the field, he landed, shut down the engine, and spoke to the landowner about what was to be sprayed and what was to be avoided. The pilot topped off the helicopter with fuel from a fuel truck. The landowner then flew around the field with the pilot so he could point out the different areas of concern. After the observation flight, the pilot loaded 40 gallons of chemicals and sprayed the first part of the field, which took about 8 minutes. The pilot returned and loaded another 50 gallons of chemicals while the engine remained operating. The pilot returned to the field and sprayed all 50 gallons. The pilot again loaded the helicopter with 50 more gallons of chemicals. During the subsequent liftoff, the helicopter felt “heavy,” but all the engine instruments were in their normal operating ranges, so he continued the flight. During the first teardrop turn back to the field to spray, the engine rpm dropped, and the pilot saw that the red “engine out” light was illuminated. The pilot immediately looked for a place to land and tried to land between two trees. The helicopter contacted the trees and rolled over, which substantially damaged the tail rotor assembly and main rotor blades. The helicopter displayed damage consistent with near-vertical impact, resulting in extensive damage to the front right side of the cockpit and aft lower fuselage areas, as well as the under fuselage-mounted chemical hopper. The tail boom was fractured aft of the fuselage attachment. The rotor head remained attached to the mast. The skids remained attached to the fuselage and were partially fractured and splayed outward on the right side. The main rotor blades remained attached to the rotor head but were fractured at different points along the length of the blades. The tail rotor assembly and portions of the blades remained attached to the tail rotor gearbox and tail boom mounts. The fuel cap remained in place at the fuel filler port. The fuel bladder was not punctured and an unquantified amount of fuel was observed in the tank such that the fuel boost pump was fully submerged. The drive shaft assembly had fractured at the flex-straps connecting the drive shaft to the main rotor transmission. The drive shaft assembly also disconnected at the engine side bolted connection to the freewheeling unit. Heavy rotational scoring was noted at several external locations along the length of the drive shaft. Rotational scoring and extensive gouging was noted on the main rotor transmission strike plate located immediately below the driveshaft flange connection to the transmission. The freewheeling unit was tested for proper functionality by checking its interactive rotation with the power turbine N2 rotor. The freewheel unit assembly and internal sprag-clutch bearing performed as expected. The output shaft assembly was disengaged and removed from the engine gearbox. All components appeared unremarkable and did not exhibit any anomalous damage. The engine was removed and sent to the manufacturer for further examination. Visual examination of the engine revealed that the compressor front support and 1st stage blades sustained heavy impact damage during the accident sequence. The 4th stage power turbine blades appeared undamaged and void of thermal distress, as did the surrounding turbine sections and exhaust plenum. The engine was placed in a test cell and successfully started, but was unable to achieve more than 115 ft-lbs of torque before the engine began to surge due to the damaged compressor blades. The compressor module was replaced with a serviceable module and the engine was started again. The engine successfully completed ground idle, flight-idle, max-continuous-power, and takeoff power runs.

Aircraft

Registration
N72BM
Reported as
Garlick Helicopters OH-58A+ (NO SERIES)
Category
Helicopter
Serial number
72-21248
Built
1972
Airframe hours
9,118
Engine
Rolls Royce T63-A-720, 420 hp, turbo shaft
Damage
Substantial damage
Flight
Aerial application · Part 137
Operator
Vertical Vegetation Management LLC
Registered owner
Vertical Vegetation Management LLC
Airworthiness certificate
Special, Restricted (Special)
Last inspection
100 hour · June 9, 2024
Airport
None
Equipment
ADS-B

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
33
Injuries
Minor
Certificate
Commercial
Medical
Class 2, Without waivers/limitations
Last flight review
March 4, 2023
Seat
Right
Restraint
4-point
Flight hours
1,415 total · 75 in this make and model · 1,334 as pilot in command · 31 in the last 90 days · 2 in the last 30 days · 2 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
130° at 10 knots
Visibility
10 statute miles
Lowest ceiling
31,000 ft broken
Temperature
86 °F, dew point 66 °F
Altimeter
30.17 inHg
Observed at
DNN, 13 nm away
METAR
KDNN 181735Z AUTO 13010KT 10SM SCT070 SCT260 BKN310 BKN350 30/19 A3017 RMK AO2 T02980188

Docket · 7

The files NTSB released with the investigation on January 22, 2025, on NTSB’s docket system: statements, records, photos and specialists’ reports. 6.5 MB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.