# NTSB CEN23LA199: Bell Helicopter Textron Canada 407, N451PH, Abbeville, LA, May 23, 2023

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 4 · Limited · Final report
- Date: May 23, 2023, 10:15 local (15:15 UTC)
- Place: Abbeville, LA
- Coordinates: 29.975151, -92.084742 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=29.9752&lon=-92.0847&mi=10
- Phase of flight: [Emergency descent](https://openairdocs.org/ntsb-phases/600) (OpenAirDocs' grouping)
- Defining event: [Autorotation: Hard landing](https://openairdocs.org/ntsb-events/092)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 4 - Basic report with no Prelim publish
- NTSB office: Central Region
- Parties: Transportation Safety Board of Canada, Bell Flight, Transport Canada, FAA Baton Rouge FSDO
- NTSB case key (mKey): 192228
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN23LA199
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/192228/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=192228
- Page: https://openairdocs.org/ntsb/CEN23LA199

## Probable cause

The pilot’s failure to maintain proper helicopter control during autorotation that resulted in an abnormal ground contact which caused the subsequent main rotor strike on the tail boom that severed the tail rotor driveshaft. Contributing to the accident was the main rotor blowback condition, due to the aft tilting of the main rotor disk.

## Findings

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

- [Rotorcraft flight control: main rotor control](https://openairdocs.org/ntsb-findings/01046710): Aircraft › Aircraft propeller/rotor · Incorrect use/operation (probable cause); cases with it: [All aircraft, 28 cases](https://openairdocs.org/ntsb-findings/01046710/cases.md)
- [Main rotor system: main rotor blade system](https://openairdocs.org/ntsb-findings/01046210): Aircraft › Aircraft propeller/rotor · Incorrect use/operation (probable cause); cases with it: [All aircraft, 60 cases](https://openairdocs.org/ntsb-findings/01046210/cases.md)
- [Performance/control parameters: prop/rotor parameters](https://openairdocs.org/ntsb-findings/01062052): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [All aircraft, 182 cases](https://openairdocs.org/ntsb-findings/01062052/cases.md)
- [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md)
- [Attention/monitoring: monitoring other person](https://openairdocs.org/ntsb-findings/02021535): Personnel issues › Psychological · Instructor/check pilot; cases with it: [All aircraft, 200 cases](https://openairdocs.org/ntsb-findings/02021535/cases.md)

## Sequence of events

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

- [Autorotation: Miscellaneous/other](https://openairdocs.org/ntsb-events/900); cases with it: [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md)
- [Autorotation: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md)
- [Autorotation: Hard landing](https://openairdocs.org/ntsb-events/092) (defining event); cases with it: [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md)
- [Autorotation: Part(s) separation from AC](https://openairdocs.org/ntsb-events/338); cases with it: [All aircraft, 563 cases](https://openairdocs.org/ntsb-events/338/sequence.md)

## Analysis

The check pilot and the pilot receiving instruction were performing initial new hire training for the commercial operator. The pilot previously performed three practice 180° autorotations, terminating with a power recovery. The pilot then performed a practice, straight-in, full down autorotation to touchdown on the sod area parallel to the runway. During the touchdown, the two pilots heard a “loud bang.” The helicopter came to rest upright on the sod area and both pilots were able to egress from the helicopter without further incident. A postflight inspection revealed that the main rotor blades struck the tail boom, severing the tail rotor driveshaft. The main rotor blades, the tail boom, and the tail rotor system sustained substantial damage. The operator reported there were no preimpact mechanical malfunctions or failures with the airframe or the engine that would have precluded normal operation. According to another helicopter manufacturer, main rotor blowback occurs when the forward portion of the helicopter’s main rotor disk is displaced upward, while the rear portion of the main rotor disk is displaced downward. If the resulting blowback is excessive, the main rotor blades may impact the tail boom. A review of the accident helicopter rotorcraft flight manual (RFM) found no information listed to provide awareness to pilots about the main rotor blowback condition.

## Aircraft

- Registration: N451PH (not matched to a registry record)
- Reported make and model: BELL HELICOPTER TEXTRON CANADA 407 (NO SERIES)
- Category: Helicopter
- Serial number: 54127
- Year built: 2012
- Airframe hours: 9305.86
- Engines: Rolls-Royce 250-C47B 675 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Phi Aviation LLC, doing business as PHI, Inc.
- Registered owner: Phi Aviation LLC
- Airworthiness certificate: Standard, Normal
- Last inspection: AAIP, May 20, 2023
- Departed: LFT, Lafayette, LA
- Destination: Same as departure
- Flight plan: Company VFR
- Airport: IYA, Abbeville Chris Crusta Meml, runway 34, 5,000 × 75 ft, grass/turf
- Equipment: Data recorder, Auto-pilot, ADS-B, Satellite tracking device, Video recording device

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Check pilot; age 31; injuries: none; commercial, flight instructor; instrument ratings: helicopter; medical: class 1, without waivers/limitations; last flight review December 4, 2022; seat: left; restraint: 4-point; flight hours: 1,689 total, 714 in this make and model, 1,602 as pilot in command, 35 in the last 90 days, 20 in the last 30 days, 1 in the last 24 hours
- Pilot; age 41; injuries: none; commercial, flight instructor; instrument ratings: helicopter; medical: class 1, without waivers/limitations; last flight review May 23, 2023; seat: right; restraint: 4-point; flight hours: 1,800 total, 8 in this make and model, 1,500 as pilot in command, 8 in the last 90 days, 8 in the last 30 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 81 °F, dew point 59 °F
- Altimeter: 29.96 inHg
- Observed at: KIYA
- METAR: KIYA 231515Z AUTO 00000KT 10SM CLR 27/15 A2996 RMK AO2 T02720148

## 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 20230523004289A](https://openairdocs.org/incident/20230523004289A), May 23, 2023: Bell Helicopter Textron Canada 407, Abbeville, LA, Substantial damage. During autorotation practices for a pilot in training (three had been performed with no touch down but the last autorotation was to be performed as a touch…

## Docket (4 files)

The files NTSB released with the investigation on July 27, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=192228. 8.1 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 2.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15686156&FileExtension=pdf&FileName=CEN23LA199%20NTSB%20Form%206120_1%20Redacted-Rel.pdf
- Accident photographs (item 2, PDF, 6 pages, 2.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15686532&FileExtension=pdf&FileName=Accident%20Photographs-Rel.pdf
- Airport information (item 3, PDF, 2 pages, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15727624&FileExtension=pdf&FileName=CEN23LA199%20-%20Airport%20Question%20Redacted-Rel.pdf
- Additional documents (item 4, PDF, 8 pages, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15686166&FileExtension=pdf&FileName=Additional%20Documents%20Redacted-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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