# NTSB ERA21LA292: Robinson Helicopter R44 II, N512RT, Princeton, KY, July 16, 2021

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Class 3 · Limited · Final report
- Date: July 16, 2021, 12:20 local (17:20 UTC)
- Place: Princeton, KY · Field
- Coordinates: 37.071389, -87.759722 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=37.0714&lon=-87.7597&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Defining event: [Maneuvering-low-alt flying: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470)
- Highest injury: Serious injuries
- Injuries: 1 serious, 1 minor
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 3
- NTSB office: Eastern Region Aviation
- Parties: FAA/FSDO
- NTSB case key (mKey): 103493
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA21LA292
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103493/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103493
- Page: https://openairdocs.org/ntsb/ERA21LA292

## 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

NTSB's coded findings; those marked are part of the probable cause.

- [Planning/preparation: weight/balance calculations](https://openairdocs.org/ntsb-findings/02061015): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Robinson Helicopter R44 II, 3 cases](https://openairdocs.org/ntsb-findings/02061015/cases.md?model=7640122), [All aircraft, 110 cases](https://openairdocs.org/ntsb-findings/02061015/cases.md)
- [Aircraft capability: maximum weight](https://openairdocs.org/ntsb-findings/01061035): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Robinson Helicopter R44 II, 9 cases](https://openairdocs.org/ntsb-findings/01061035/cases.md?model=7640122), [All aircraft, 152 cases](https://openairdocs.org/ntsb-findings/01061035/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Prior to flight: Preflight or dispatch event](https://openairdocs.org/ntsb-events/030); cases with it: [Robinson Helicopter R44 II, 2 cases](https://openairdocs.org/ntsb-events/030/sequence.md?model=7640122), [All aircraft, 355 cases](https://openairdocs.org/ntsb-events/030/sequence.md)
- [Maneuvering-low-alt flying: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470) (defining event); cases with it: [Robinson Helicopter R44 II, 95 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7640122), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)

## 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](https://openairdocs.org/aircraft/N512RT), registered now, S/N 11465, built 2006 (OpenAirDocs)
- Reported make and model: ROBINSON HELICOPTER COMPANY R44 II (NO SERIES)
- Registry model: [Robinson Helicopter R44 II](https://openairdocs.org/model/robinson-helicopter-r44-ii) (registry code 7640122) (OpenAirDocs)
- Registry engine: [Lycoming IO-540-AE1A5](https://openairdocs.org/engine/lycoming-io-540-ae1a5) (registry code 41899, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 11465
- Year built: 2006
- Airframe hours: 2645
- Engines: 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

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 75; injuries: serious; 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
- 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

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 20210716006909A](https://openairdocs.org/incident/20210716006909A), Jul 16, 2021: Robinson Helicopter Company R44 II, Lewisburg, KY, Substantial damage. According to the passenger, on the third load the helicopter came off the truck, turned directly into the wind. As the aircraft cleared the power lines the low…

## Docket (7 files)

The files NTSB released with the investigation on July 26, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103493. 21.7 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 3.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12721288&FileExtension=pdf&FileName=6120%20LA292-5JY0M73_Redacted-Rel.pdf
- Record of conversation pilot's wife (item 2, PDF, 1 page, 53 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12722396&FileExtension=pdf&FileName=Record%20of%20Conversation%20N512RT%20KB-Rel.pdf
- FAA record of conversation with pilot (item 3, PDF, 2 pages, 849 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12722495&FileExtension=pdf&FileName=FAA_Form_1360-33,%20Thomas%20Bolls_Redacted-Rel.pdf
- FAA inspector examination notes (item 4, PDF, 11 pages, 2.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12722723&FileExtension=pdf&FileName=Inspector%20Statement%20R44%20N512RT-Rel.pdf
- Maintenance logbook excerpts (item 5, PDF, 7 pages, 14.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12722764&FileExtension=pdf&FileName=Maintenace%20logbook%20excepts%20LA292_Redacted-Rel.pdf
- N512RT weight and balance calculation (item 6, PDF, 1 page, 79 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12722109&FileExtension=pdf&FileName=R44%20W%26B.1-Rel.pdf
- Photo array (item 7, PDF, 2 pages, 358 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12723639&FileExtension=pdf&FileName=Photo%20array%20LA292-Rel.pdf

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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