# NTSB WPR21LA341: Robinson R44, N544SH, Camp Verde, AZ, August 28, 2021

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 4 · Limited · Final report
- Date: August 27, 2021, 18:30 local (Aug 28, 2021, 01:30 UTC)
- Place: Camp Verde, AZ
- Coordinates: 34.296111, -111.79194 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=34.2961&lon=-111.7919&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Defining event: [Landing-flare/touchdown: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 4 - Basic report with no Prelim publish
- NTSB office: Western Pacific Region
- Parties: FSDO
- NTSB case key (mKey): 103849
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR21LA341
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103849/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103849
- Page: https://openairdocs.org/ntsb/WPR21LA341

## Probable cause

The pilot's inadequate preflight performance calculations which resulted in an aborted takeoff and collision with trees.

## Findings

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

- [Object/animal/substance: tree(s)](https://openairdocs.org/ntsb-findings/03022020): Environmental issues › Physical environment · Effect on operation; cases with it: [Robinson Helicopter R44 II, 9 cases](https://openairdocs.org/ntsb-findings/03022020/cases.md?model=7640122), [All aircraft, 933 cases](https://openairdocs.org/ntsb-findings/03022020/cases.md)
- [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Robinson Helicopter R44 II, 40 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=7640122), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md)
- [Planning/preparation: performance calculations](https://openairdocs.org/ntsb-findings/02061010): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Robinson Helicopter R44 II, 3 cases](https://openairdocs.org/ntsb-findings/02061010/cases.md?model=7640122), [All aircraft, 114 cases](https://openairdocs.org/ntsb-findings/02061010/cases.md)
- [Terrain: mountainous/hilly terrain](https://openairdocs.org/ntsb-findings/03021010): Environmental issues › Physical environment · Effect on equipment (probable cause); cases with it: [Robinson Helicopter R44 II, 4 cases](https://openairdocs.org/ntsb-findings/03021010/cases.md?model=7640122), [All aircraft, 329 cases](https://openairdocs.org/ntsb-findings/03021010/cases.md)
- [Temp/humidity/pressure: high density altitude](https://openairdocs.org/ntsb-findings/03031020): Environmental issues › Conditions/weather/phenomena · Effect on operation (probable cause); cases with it: [Robinson Helicopter R44 II, 11 cases](https://openairdocs.org/ntsb-findings/03031020/cases.md?model=7640122), [All aircraft, 278 cases](https://openairdocs.org/ntsb-findings/03031020/cases.md)

## Sequence of events

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

- [Landing-flare/touchdown: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) (defining event); cases with it: [Robinson Helicopter R44 II, 16 cases](https://openairdocs.org/ntsb-events/490/sequence.md?model=7640122), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md)

## Analysis

The pilot reported that, while taking off from a remote mountainous site, the helicopter encountered some turbulent air and the main rotor RPM decayed. He elected to abort the takeoff and land at a site about 20-30 ft from the original location. During the landing, the main rotor blades struck a tree. The helicopter sustained substantial damage to main rotor blades and main rotor hub assembly. The pilot reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation. He also reported that the accident could have been avoided by taking more time to calculate and determine the density altitude and out of ground effect performance of the helicopter at the time of the accident.

## Aircraft

- Registration: [N544SH](https://openairdocs.org/aircraft/N544SH), registered now, S/N 10818, built 2005 (OpenAirDocs)
- Reported make and model: ROBINSON R44 (II)
- Registry model: [Robinson Helicopter R44 II](https://openairdocs.org/model/robinson-helicopter-r44-ii) (registry code 7640122) (OpenAirDocs)
- Registry engine: [Lycoming IO-540 series](https://openairdocs.org/engine/lycoming-io-540-series) (registry code 41585, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 10818
- Year built: 2005
- Airframe hours: 3724.6
- Engines: Lycoming IO-540-AEIA5 260 horsepower reciprocating
- Damage: Substantial damage
- Flight: Public aircraft - local, Part 91
- Operator: Yavapai County
- Registered owner: Yavapai County
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, August 9, 2021, 12.7 hours before
- Departed: KPRC, Prescott, AZ
- Destination: KPRC, Prescott, AZ
- Airport: N/A
- Equipment: ADS-B

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 48; injuries: none; commercial; medical: class 2, without waivers/limitations; last flight review August 13, 2020; seat: right; flight hours: 971 total, 968 in this make and model, 873 as pilot in command, 22 in the last 90 days, 12 in the last 30 days, 6 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Dusk
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 68 °F, dew point 50 °F
- Altimeter: 29.75 inHg
- Observed at: KPRC, 38 nm away
- METAR: METAR KPRC 271253Z 18004KT 9SM CLR 16/08 A3007 RMK AO2 SLP096 T01560083=

## Docket (2 files)

The files NTSB released with the investigation on December 14, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103849. 7.4 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 4.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12834026&FileExtension=pdf&FileName=NTSB%206120%20Redacted%20Flattened-Rel.pdf
- Photos (item 2, PDF, 2 pages, 2 photos, 2.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12994223&FileExtension=pdf&FileName=Photo%2011-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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