# NTSB CEN10CA485: Robinson Helicopter R22 Beta, N404LE, Mack, CO, August 14, 2010

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Data collection · Final report
- Date: August 14, 2010, 08:50 local (14:50 UTC)
- Place: Mack, CO
- Coordinates: 39.267501, -108.858329 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=39.2675&lon=-108.8583&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Defining event: [Maneuvering: Loss of control in flight](https://openairdocs.org/ntsb-events/240)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report March 16, 2011
- Report: Approved by Office Director
- NTSB office: Central Region
- Parties: FAA/FSDO
- NTSB case key (mKey): 77003
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN10CA485
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/77003/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=77003
- Page: https://openairdocs.org/ntsb/CEN10CA485

## Probable cause

The flight instructor's failure to maintain control of the helicopter during a practice autorotation, which resulted in a hard landing.

## Findings

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

- [Personnel issues](https://openairdocs.org/ntsb-findings/02040000): Personnel issues › Action/decision · Instructor/check pilot (probable cause); cases with it: [All aircraft, 56 cases](https://openairdocs.org/ntsb-findings/02040000/cases.md)
- [Performance/control parameters](https://openairdocs.org/ntsb-findings/01062000): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [All aircraft, 1,269 cases](https://openairdocs.org/ntsb-findings/01062000/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: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md)
- [Maneuvering: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md)

## Analysis

The certificated flight instructor (CFI) and his student were practicing a 180-degree autorotation with a power recovery occurring at the hover. The helicopter's sink rate increased dramatically in the flare, about 40 feet above the ground. The CFI initiated a go-around by increasing power, raising the collective, and pushing the cyclic forward. The helicopter continued to descend and contacted the runway in a level attitude. After it came to a stop, the CFI confirmed that the main rotor blade had struck the tail boom. The instructor reported that there were no preimpact mechanical deficiencies with the helicopter.

## Factual narrative

The certified flight instructor and his student were practicing a 180 degree autorotation with a power recovery to a hover, when the helicopter's sink rate increased dramatically in the flare about 40 feet above the ground. The flight instructor called for a go-around and increased power, raised the collective, and pushed the cyclic forward. The helicopter continued to descend and contacted the runway in a level attitude. After it came to a stop, a vibration was felt and the instructor confirmed that the main rotor blade had struck the tail boom. The instructor reported that there were no mechanical deficiencies with the helicopter.

## Aircraft

- Registration: N404LE (not matched to a registry record)
- Reported make and model: ROBINSON HELICOPTER R22 BETA
- Category: Helicopter
- Serial number: 4040
- Engines: LYCOMING O-360-J2A 145 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: North Canyon Helicopters
- Registered owner: Nebo Helicopter Rebuild LLC
- Airworthiness certificate: Standard, Normal
- Departed: Grand Junction, CO
- Destination: C07, Mack, CO
- Flight plan: Unknown
- Airport: C07, Mack-Mesa Airport, runway 07

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 36; flight instructor, commercial; instrument ratings: helicopter; medical: class 2; flight hours: 1,471 total, 1,313 in this make and model

## Weather

- Conditions: Visual (VMC), Day

## Docket (1 files)

The files NTSB released with the investigation on September 29, 2010, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=77003. 400 KB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 400 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40336561&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.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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