ERA23LA332

NTSB accident investigation · Bell 47G-5 · Mifflinville, PA · August 12, 2023

Accident · FatalClass 3 · LimitedFinal report
Date
August 12, 2023, 09:50 local (13:50 UTC)
Place
Mifflinville, PA
Injuries
1 fatal
Damage
Destroyed
Phase of flight
Maneuvering
Aircraft
N1503LBell 47G-5
Defining event
Maneuvering-low-alt flying: Low altitude operation/event
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Eastern Region Aviation
Parties
FAA/FSDO
FAA report
20230812011319A
Case key
192850

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

The pilot’s failure to see and avoid powerlines during an aerial application flight.

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.

Object/animal/substance: wireEnvironmental issues › Physical environment · Awareness of conditionBell 47G-5: 3 casesAll aircraft: 588 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 aerial application helicopter departed from a chemical truck staging area to a nearby corn field, where he was performing his eighth application flight of the day. There were no witnesses to the accident and the pilot was fatally injured. The accident site was located near the edge of the cornfield, which was bordered by a road, trees, and a powerline. The helicopter’s spray boom and one landing gear skid were separated from the fuselage and found in a tree entangled with the power lines. The helicopter’s fuselage, engine, and fuel tanks were consumed by a postimpact fire. Given this information, it is most likely that the helicopter impacted the powerline while maneuvering at low level above the corn field. The pilot had received training about 13 years before the accident to act as pilot-in-command of aerial application operations. The training program included a skills test to demonstrate safe low-level maneuvering and how to approach the working area to locate obstacles. The extent to which the pilot had conducted a preflight assessment of the corn field for obstacles and was aware of the location of the wires could not be determined. A postaccident autopsy of the pilot’s remains identified cardiovascular disease that would have increased his risk of experiencing a sudden impairing or incapacitating cardiac event, such as arrhythmia, chest pain, or heart attack. The autopsy did not provide specific evidence that such an event occurred; however, such an event would also not leave evidence readily identifiable by an autopsy if it occurred shortly before death. Therefore, whether the pilot was incapacitated to some degree by a cardiac event that preceded the wire strike could not be determined.

Factual narrative

On August 12, 2023, about 0950 eastern daylight time, a Bell 47G-5 helicopter, N1503L, was destroyed when it was involved in an accident near Mifflinville, Pennsylvania. The pilot was fatally injured. The helicopter was operated as a Title 14 Code of Federal Regulations Part 137 aerial application flight. The pilot’s brother, who was also a helicopter pilot, stated that on the day of the accident, he was operating a truck with chemicals in it and the pilot was flying the aerial application helicopter. The pilot had already made about seven application flights that morning and had just taken off from near the truck with the eighth load. The truck was parked in a field about 2 miles away from the corn field that the pilot was spraying. The pilot’s brother subsequently received a telephone call and learned that the helicopter had crashed. As he was driving up to the accident site, the pilot’s brother noticed power lines down in the street; he also noticed the power lines entangled with the helicopter’s skid, and the spraying boom located in a tree by the road. The accident site was in the corn field about 20 yards from the road. The helicopter came to rest on its left side and a postaccident fire consumed the engine and fuel tanks. The tail rotor was found about 20 yards from the main wreckage. The spray boom and one skid were found about 30 yards away in a tree entangled in the powerlines. The pilot completed an aerial application training program and was signed off to act as pilot in command of aerial applications on July 3, 2010. The training program consisted of a skills test to demonstrate safety pertaining to low-level maneuvering and how to approach the working area to locate obstacles. Forensic Pathology Associates, Allentown, Pennsylvania, performed an autopsy of the pilot’s remains for the Columbia County Coroner’s Office. According to the autopsy report, the pilot’s cause of death was multiple injuries, and his manner of death was accidental. The pilot’s autopsy identified coronary artery disease, including an area of plaque causing 90% narrowing of the obtuse marginal artery (a branch of the left circumflex coronary artery), as well as up to 25% narrowing of the other coronary arteries by plaque. The heart was described as enlarged, with right ventricular dilatation and left ventricular hypertrophy. There was a 0.5 cm × 0.5 cm × 0.3 cm area of white discoloration of the anterior left cardiac ventricle. Microscopic examination of the heart muscle showed enlarged muscle cells.

Aircraft

Registration
N1503L
Reported as
Bell 47G-5
Category
Helicopter
Serial number
25042
Built
1971
Airframe hours
21,036
Engine
Lycoming VO-435-B1A, 260 horsepower, reciprocating
Damage
Destroyed
Fire
On-Ground
Flight
Aerial application · Part 137
Operator
Triple F Flying Inc
Registered owner
Triple F Flying Inc
Airworthiness certificate
Special, Restricted (Special)
Last inspection
100 hour · April 14, 2023
Equipment
Handheld GPS

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
39
Injuries
Fatal
Certificate
Commercial
Airplane ratings
Single-engine land, Single-engine sea
Medical
Class 2, Without waivers/limitations
Last flight review
April 26, 2023
Seat
Right
Toxicology
Performed
Flight hours
1,325 total · 490 in this make and model · 175 in the last 90 days · 74 in the last 30 days · 5 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
9 statute miles
Lowest ceiling
10,000 ft overcast
Temperature
70 °F, dew point 63 °F
Altimeter
29.92 inHg
Observed at
AVP, 32 nm away
METAR
KAVP 121354Z 00000KT 9SM OVC100 21/17 A2992 RMK AO2 SLP123 T02060167

Docket · 6

The files NTSB released with the investigation on July 22, 2025, on NTSB’s docket system: statements, records, photos and specialists’ reports. 94.5 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.