# NTSB WPR12TA120: Eurocopter AS 350 B3, N341HP, Napa, CA, March 1, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Final report - Date: February 29, 2012, 17:15 local (Mar 1, 2012, 01:15 UTC) - Place: Napa, CA - Coordinates: 38.207778, -122.275001 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=38.2078&lon=-122.2750&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 February 14, 2013 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration FSDO - NTSB case key (mKey): 83021 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR12TA120 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/83021/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=83021 - Page: https://openairdocs.org/ntsb/WPR12TA120 ## Probable cause The flight instructor’s improper use of the collective control during a practice hovering autorotation, which resulted in a hard landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [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) - [Use of equip/info: use of policy/procedure](https://openairdocs.org/ntsb-findings/02063032): Personnel issues › Task performance · Instructor/check pilot (probable cause); cases with it: [Eurocopter AS 350 B3, 3 cases](https://openairdocs.org/ntsb-findings/02063032/cases.md?model=8680954), [All aircraft, 191 cases](https://openairdocs.org/ntsb-findings/02063032/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-hover: 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: 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 The flight instructor reported that while hovering about 3 feet above the ground, he performed an autorotation demonstration for the second pilot. Although the flight instructor raised the collective to arrest the descent before landing, the helicopter made a firm landing, which resulted in substantial damage to the tailboom. The flight instructor reported no preimpact mechanical malfunction or failure that would have precluded normal operation. The Federal Aviation Administration’s helicopter flying handbook identifies the proper techniques for practice autorotation maneuvers from altitude and indicates that one of the common errors that can occur during hovering autorotations is the pilot’s failure to apply up-collective pitch properly, which can result in a hard landing. ## Factual narrative On February 29, 2012, about 1715 Pacific standard time, a Eurocopter AS 350-B3, N341HP, made a hard landing at the Napa County Airport, Napa, California. The helicopter was substantially damaged during landing. The commercial pilot held a certified flight instructor (CFI) certificate, and he was providing instruction to the second pilot, who held a commercial pilot certificate. Neither pilot was injured. The California Highway Patrol (CHP), Sacramento, California, owned and operated the public use helicopter. The flight was performed under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed. No flight plan was filed for the local area instructional flight that originated from Napa about 1600. CHP management personnel reported that, at the time of the accident, the CFI was handling the flight controls. While hovering about 3 feet above ground level, the CFI performed an autorotation demonstration for the second pilot. Although the CFI raised the collective to arrest the descent prior to landing, the helicopter made a firm touchdown. The CFI reported no mechanical malfunctions or failures with the helicopter prior to impact. The CFI stated that his total flight experience totaled 2,783 hours, of which 409 were accumulated while acting in the capacity of a flight instructor. During a subsequent examination of the tail boom, numerous dimples in the skin were noted near the area where the tail boom attaches to the fuselage. The tail boom was removed from the helicopter and transported to Eurocopter's Texas facility for repair. The Federal Aviation Administration Rotorcraft Flying Handbook states that as part of the technique for practice autorotation maneuvers from altitude, the pilot should "smoothly, but firmly lower the collective pitch control to the full down position, maintaining rotor r.p.m. in the green arc with throttle." To practice hovering autorotations, it instructs the pilot to "firmly roll the throttle to the engine idle position" It further states that, "As the throttle is closed, apply proper antitorque pedal to maintain heading" and "Do not adjust the collective pitch on entry." It then instructs that "When the helicopter has settled to approximately 1 foot AGL, apply upward collective pitch control while holding the throttle in the idle detent position to slow the descent and cushion the landing," and notes that "usually the full amount of collective pitch is required." The manual lists one of the common errors of practice hovering autorotations to be the pilot's failure to "apply up-collective pitch properly, resulting in a hard touchdown." ## Aircraft - Registration: [N341HP](https://openairdocs.org/deregistered/N341HP-2025-11-14), registration cancelled 2025-11-14, S/N 3407, built 2001 (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-2B series](https://openairdocs.org/engine/turbomeca-arrius-2b-series) (registry code 60013, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 3407 - Airframe hours: 8027 - Engines: TURBOMECA ARRIUS 2B 515 horsepower turbo shaft - Damage: Substantial damage - Flight: Public aircraft - state, Public use - Operator: California Highway Patrol - Registered owner: California Highway Patrol - Airworthiness certificate: Standard, Normal - Departed: Napa, CA - Destination: Napa, CA - Airport: KAPC, Napa County Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 44; injuries: none; commercial, private, flight instructor; airplane ratings: single-engine land; instrument ratings: helicopter; medical: class 2, without waivers/limitations; last flight review August 4, 2011; seat: left; flight hours: 2,783 total, 2,259 in this make and model, 2,699 as pilot in command, 43 in the last 90 days, 11 in the last 30 days, 1 in the last 24 hours - Pilot; age 45; injuries: none; commercial; instrument ratings: helicopter; medical: class 2, without waivers/limitations; last flight review August 31, 2010; seat: right; flight hours: 5,364 total, 3,404 in this make and model, 4,919 as pilot in command, 29 in the last 90 days, 20 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 11 knots - Visibility: 10 statute miles - Lowest ceiling: 10,000 ft overcast - Temperature: 50 °F, dew point 36 °F - Altimeter: 30.19 inHg - Observed at: APC ## Other investigations on N341HP (1) 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. - [NTSB LAX03GA145](https://openairdocs.org/ntsb/LAX03GA145), May 1, 2003: Eurocopter France AS350B3 (N341HP), Napa, CA, substantial damage. Probable cause: the pilot under instruction's inadvertent activation of the collective manual fuel slide lock, which led to engine and main rotor overspeeds due to excessive fuel flow during power application. This… ## Docket (3 files) The files NTSB released with the investigation on December 19, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=83021. 11.1 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 863 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40382285&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - FAA-H-8083-21A Helicopter Flying Handbook Chapter 11 (item 2, .PDF, 4.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40378060&FileExtension=.PDF&FileName=FAA-H-8083-21A%20Helicopter%20Flying%20Handbook%20Chapter%2011-Master.PDF - Photo-Right side of tail boom and fuselage (item 3, .PDF, 5.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377155&FileExtension=.PDF&FileName=Photo-Right%20side%20of%20tail%20boom%20and%20fuselage-Master.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. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.