# NTSB WPR10CA028: Eurocopter AS 350 B3, N105LN, Marana, AZ, October 22, 2009

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Data collection · Final report
- Date: October 22, 2009, 09:15 local (16:15 UTC)
- Place: Marana, AZ
- Coordinates: 32.509723, -111.325279
- Nearby events: https://openairdocs.org/map.md?lat=32.5097&lon=-111.3253&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Defining event: [Landing-flare/touchdown: Hard landing](https://openairdocs.org/ntsb-events/092)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report March 3, 2010
- Report: Approved by Office Director
- NTSB office: Western Pacific Region
- Parties: Federal Aviation Administration
- NTSB case key (mKey): 74943
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR10CA028
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/74943/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=74943
- Page: https://openairdocs.org/ntsb/WPR10CA028

## Probable cause

The improper use of the throttle by the pilot receiving instruction, and the check pilot's inadequate supervision and delayed remedial action, which resulted in the collision with terrain.

## Findings

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

- [Engine controls](https://openairdocs.org/ntsb-findings/01057600): Aircraft › Aircraft power plant · Incorrect use/operation (probable cause); cases with it: [Eurocopter AS 350 B3, 1 case](https://openairdocs.org/ntsb-findings/01057600/cases.md?model=8680954), [All aircraft, 51 cases](https://openairdocs.org/ntsb-findings/01057600/cases.md)
- [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Eurocopter AS 350 B3, 14 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=8680954), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md)
- [Action: delayed action](https://openairdocs.org/ntsb-findings/02041025): Personnel issues › Action/decision · Instructor/check pilot (probable cause); cases with it: [Eurocopter AS 350 B3, 5 cases](https://openairdocs.org/ntsb-findings/02041025/cases.md?model=8680954), [All aircraft, 894 cases](https://openairdocs.org/ntsb-findings/02041025/cases.md)

## Sequence of events

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

- [Maneuvering: Simulated/training event](https://openairdocs.org/ntsb-events/600); cases with it: [Eurocopter AS 350 B3, 4 cases](https://openairdocs.org/ntsb-events/600/sequence.md?model=8680954), [All aircraft, 173 cases](https://openairdocs.org/ntsb-events/600/sequence.md)
- [Autorotation: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Eurocopter AS 350 B3, 1 case](https://openairdocs.org/ntsb-events/060/sequence.md?model=8680954), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md)
- [Landing-flare/touchdown: Hard landing](https://openairdocs.org/ntsb-events/092) (defining event); cases with it: [Eurocopter AS 350 B3, 9 cases](https://openairdocs.org/ntsb-events/092/sequence.md?model=8680954), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md)

## Analysis

During a practice hovering autorotation the helicopter impacted terrain, which resulted in substantial damage to the tailboom. The left seat check pilot who was giving instruction to the right seat pilot reported that a clear, flat area had been identified for hovering autorotation practice. After being briefed by the check pilot, the right seat pilot brought the helicopter up to a 3- to 5-foot hover. The check pilot stated, "I reminded the pilot that he would retard the throttle. [The] aircraft drifted up to less than 10 feet, [and] before I could correct the altitude deviation the [right seat] pilot aggressively retarded the throttle. The aircraft was allowed to settle to approximately 4 feet before the collective pull was initiated, but I was unable to sufficiently arrest the descent." An examination of the helicopter by a Federal Aviation Administration airworthiness inspector revealed that the tailboom had been wrinkled as a result of the impact with terrain.

## Factual narrative

During a practice hovering autorotation the helicopter impacted terrain, which resulted in substantial damage to the tailboom. The left seat check pilot who was giving instruction to the right seat pilot, reported that a clear, flat area had been identified for hovering autorotation practice. After being briefed by the check pilot, the right seat pilot brought [the] helicopter up to a 3 to 5 foot hover. The check pilot stated, "I reminded the pilot that he would retard the throttle. [The] aircraft drifted up to less than 10 feet, [and] before I could correct the altitude deviation the [right seat] pilot aggressively retarded the throttle. The aircraft was allowed to settle to approximately 4 feet before the collective pull was initiated, but I was unable to sufficiently arrest the descent." An examination of the helicopter by a Federal Aviation Administration airworthiness inspector revealed that the tailboom had been wrinkled as a result of impact with terrain.

## Aircraft

- Registration: [N105LN](https://openairdocs.org/deregistered/N105LN-2010-10-21), registration cancelled 2010-10-21, S/N 3249, built 1999 (OpenAirDocs)
- Reported make and model: EUROCOPTER AS 350 B3
- Registry model: [Eurocopter AS 350 B3](https://openairdocs.org/model/eurocopter-as-350-b3) (registry code 8680954) (OpenAirDocs)
- Registry engine: [Turbomeca ARRIUS-2B1](https://openairdocs.org/engine/turbomeca-arrius-2b1) (registry code 60015, turbo-shaft) (OpenAirDocs)
- Category: Helicopter
- Serial number: 3249
- Airframe hours: 6244
- Engines: Turbomeca Arrius 2B1 turbo shaft
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Air Methods
- Registered owner: Wells Fargo Bank Northwest NA Trustee
- Airworthiness certificate: Standard, Normal
- Last inspection: AAIP, October 21, 2009, 47 hours before
- Departed: MZJ, Marana, AZ
- Destination: MZJ, Marana, AZ
- Flight plan: Company VFR
- Airport: AVQ, Marana Regional Airport, runway 12, 6,901 × 100 ft, dirt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Flight instructor; age 40; injuries: none; commercial; instrument ratings: helicopter; medical: class 2, without waivers/limitations; last flight review July 18, 2009; seat: left; flight hours: 4,500 total, 400 in this make and model
- Pilot; age 61; injuries: none; commercial; medical: class 2; seat: right
- Pilot; age 60; injuries: none; airline transport, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: helicopter, airplane; medical: class 2, with waivers/limitations; last flight review January 14, 2009; seat: right; flight hours: 12,000 total, 500 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 40 statute miles
- Lowest ceiling: none
- Temperature: 70 °F, dew point 34 °F
- Altimeter: 30.01 inHg
- Observed at: AVG

## 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 20091022022229A](https://openairdocs.org/incident/20091022022229A), Oct 22, 2009: Snias AS350B3, Tucson, AZ, Substantial damage. Mr. Teeb was giving [privacy data omitted] a check ride following an accident [privacy data omitted] had in September, 2009. After 30 minutes of maneuvers, Mr.…

## Docket (1 files)

The files NTSB released with the investigation on November 17, 2009, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=74943. 3.7 MB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40321225&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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