ERA21LA292

NTSB accident investigation · Robinson Helicopter R44 II · Princeton, KY · July 16, 2021

Accident · Serious injuriesClass 3 · LimitedFinal report
Date
July 16, 2021, 12:20 local (17:20 UTC)
Place
Princeton, KY · Field
Injuries
1 serious, 1 minor
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N512RTRobinson Helicopter R44 II
Defining event
Maneuvering-low-alt flying: Collision with terr/obj (non-CFIT)
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
20210716006909A
Case key
103493

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 inadequate preflight planning in that he failed to accurately determine the takeoff weight of the helicopter, which resulted in exceeding the helicopter’s maximum weight capability.

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.

Aircraft capability: maximum weightAircraft › Aircraft oper/perf/capability · Capability exceededRobinson Helicopter R44 II: 9 casesAll aircraft: 152 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

Before takeoff to spray a nearby cornfield, the helicopter was filled with about 50 gallons of spraying solution and a passenger was onboard to assist the pilot with the navigation system. According to the pilot, shortly after takeoff, the low rotor rpm warning light illuminated, and the helicopter “just wouldn’t fly.” The pilot was unable to stay aloft and made a hard landing in a field. An examination of the helicopter revealed substantial damage to the airframe and partial separation of the tail boom. Examination of the engine and its components revealed no anomalies that would have resulted in a loss of power. The helicopter’s estimated takeoff weight was 2,641.4 lbs., which was 141.4 lbs. over its maximum gross weight of 2,500 lbs. After the accident, the pilot told his spouse that he knew the helicopter was “barely overweight but felt it would be fine.” Given that no mechanical anomalies were found, it is likely that the loss of rotor rpm was the result of operating the helicopter in an overweight condition.

Factual narrative

On July 16, 2021, about 1330 eastern daylight time, a Robinson R44, N512RT, was substantially damaged when it was involved in an accident near Princeton, Kentucky. The commercial pilot received serious injuries, and the pilot-rated passenger received minor injuries. The helicopter was operated as a Title 14 Code of Federal Regulations Part 137 aerial application flight. According to the pilot, the purpose of the flight was to spray a nearby cornfield. He reported that they were having a problem with the agricultural mapping and navigation system installed in the helicopter, so the passenger, who was also an aerial application pilot, was onboard to assist with the operation of the system. They had flown two loads without incident. The pilot reported that they took off on the third load, and “after about a couple of hundred yards,” the low rotor rpm warning light illuminated. Prior to takeoff, the helicopter was filled with about 50 gallons of spraying solution. They knew it was barely overweight but felt it would be fine. After the accident, the pilot told his wife that “the helicopter just wouldn't fly, and he was getting a low rotor rpm light.” As the pilot maneuvered the helicopter for landing, the left spray boom contacted trees, and the helicopter landed hard, bounced, and rolled onto its left side. The passenger exited the helicopter and assisted the pilot in getting out. According to the pilot’s wife, after the accident, the pilot told her that before takeoff, the helicopter was filled with about 50 gallons of spraying solution. She stated that the pilot told her he “knew it was barely overweight but felt it would be fine.” She further stated that the pilot told her that “the helicopter just wouldn't fly.” Examination of the helicopter by a Federal Aviation Administration inspector revealed substantial damage to the airframe and partial separation of the tail boom. An examination was conducted on the engine and its components. No anomalies were noted during the examination. The maximum gross weight for the helicopter was 2,500 lbs. A weight and balance calculation revealed that the helicopter’s estimated weight at the time of the accident was 2,641.4 lbs.

Aircraft

Registration
N512RT
Reported as
Robinson Helicopter R44 II (NO SERIES)
Category
Helicopter
Serial number
11465
Built
2006
Airframe hours
2,645
Engine
Lycoming IO-540-AE1A5, 235 horsepower, reciprocating
Damage
Substantial damage
Flight
Aerial application · Part 137
Operator
Tomkat Aviation LLC
Registered owner
Tomkat Aviation LLC
Airworthiness certificate
Standard, Normal
Last inspection
Annual · October 1, 2020 · 52.5 hours before
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 · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
75
Injuries
Serious
Certificate
Commercial
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Helicopter, Airplane
Medical
Class 2, With waivers/limitations
Last flight review
November 3, 2020
Seat
Right
Restraint
4-point
Flight hours
10,558 total · 104 in this make and model · 10,378 as pilot in command · 39 in the last 90 days · 11 in the last 30 days · 3 in the last 24 hours
Role
Pilot-rated passenger
Age
49
Injuries
None
Airplane ratings
Single-engine land
Medical
Class 2, With waivers/limitations
Seat
Left
Restraint
4-point

Weather

Conditions
Visual (VMC) · Day
Wind
200° at 9 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
84 °F, dew point 73 °F
Altimeter
30.09 inHg
Observed at
BWG, 15 nm away

Docket · 7

The files NTSB released with the investigation on July 26, 2023, on NTSB’s docket system: statements, records, photos and specialists’ reports. 21.7 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.