# NTSB GAA17CA434: Robinson Helicopter R22, N28VH, Bozeman, MT, July 21, 2017 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: July 21, 2017, 08:30 local (14:30 UTC) - Place: Bozeman, MT - Coordinates: 45.7775, -111.151947 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.7775&lon=-111.1519&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 March 14, 2018 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 95648 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA17CA434 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/95648/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=95648 - Page: https://openairdocs.org/ntsb/GAA17CA434 ## Probable cause The flight instructor’s unstabilized 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 · Instructor/check pilot (probable cause); cases with it: [Robinson Helicopter R22, 18 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=7640102), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters: descent rate](https://openairdocs.org/ntsb-findings/01062037): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Robinson Helicopter R22, 5 cases](https://openairdocs.org/ntsb-findings/01062037/cases.md?model=7640102), [All aircraft, 242 cases](https://openairdocs.org/ntsb-findings/01062037/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: [Robinson Helicopter R22, 4 cases](https://openairdocs.org/ntsb-findings/01062052/cases.md?model=7640102), [All aircraft, 182 cases](https://openairdocs.org/ntsb-findings/01062052/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: [Robinson Helicopter R22, 3 cases](https://openairdocs.org/ntsb-events/900/sequence.md?model=7640102), [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) - [Autorotation: Hard landing](https://openairdocs.org/ntsb-events/092) (defining event); cases with it: [Robinson Helicopter R22, 13 cases](https://openairdocs.org/ntsb-events/092/sequence.md?model=7640102), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) - [Autorotation: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Robinson Helicopter R22, 6 cases](https://openairdocs.org/ntsb-events/060/sequence.md?model=7640102), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) ## Analysis According to the helicopter flight instructor, he was demonstrating simulated 180° right turn autorotations. He reported that, during the entry of the third autorotation, the helicopter attitude was excessively nose low and the descent rate was high. He initiated a power-on recovery; however, the flare was initiated too late. He applied forward cyclic to level the skids and increased collective to its mechanical limit, but the helicopter touched down hard, and one of the main rotor blades struck the tailboom. The helicopter sustained substantial damage to the tailboom. The pilot reported in the National Transportation Safety Board's Pilot Aircraft Accident Report, "The event could have been avoided by recovering the autorotation sooner and doing a go-around." The operator reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation. ## Factual narrative According to the helicopter flight instructor, he was demonstrating simulated 180° right turn autorotations. He reported that during the entry of the third autorotation, the helicopter attitude was excessively nose low and the rate of descent was high. He initiated a power-on recovery; however, the flare was initiated too late. He applied forward cyclic to level the skids and increased collective to its mechanical limit, but the helicopter touched down and one of the main rotor blades struck the tailboom. The helicopter sustained substantial damage to the tailboom. The pilot reported in the National Transportation Safety Board's, Pilot Aircraft Accident Report, "The event could have been avoided by recovering the autorotation sooner and doing a go-around." The operator reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation. ## Aircraft - Registration: [N28VH](https://openairdocs.org/deregistered/N28VH-2022-10-18), registration cancelled 2022-10-18, S/N 3687, built 2004 (OpenAirDocs) - Reported make and model: ROBINSON HELICOPTER COMPANY R22 (MARINER) - Registry model: [Robinson Helicopter R22](https://openairdocs.org/model/robinson-helicopter-r22) (registry code 7640102) (OpenAirDocs) - Registry engine: [Lycoming O-360 series](https://openairdocs.org/engine/lycoming-o-360-series) (registry code 41575, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 3687 - Year built: 2004 - Airframe hours: 2640.9 - Engines: LYCOMING O-360 SERIES reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Rocky Mountain Rotors LLC - Registered owner: Rocky Mountain Rotors LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 26, 2017 - Departed: KBZN, Bozeman, MA - Destination: KBZN, Bozeman, MA - Airport: BZN, Bozeman Yellowstone Intl ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 24; injuries: none; commercial, flight instructor; instrument ratings: helicopter; medical: class 2, without waivers/limitations; last flight review June 30, 2017; seat: left; restraint: 3-point; flight hours: 302 total, 182 in this make and model, 208 as pilot in command, 70 in the last 90 days, 41 in the last 30 days, 1 in the last 24 hours - Student pilot; age 31; injuries: none; private, student; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, without waivers/limitations; last flight review March 12, 2017; seat: right; restraint: 3-point; flight hours: 193 total, 52 in this make and model, 61 as pilot in command, 54 in the last 90 days, 24 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 61 °F, dew point 43 °F - Altimeter: 30.13 inHg - Observed at: KBZN, 1 nm away ## 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 20170721009129A](https://openairdocs.org/incident/20170721009129A), Jul 21, 2017: Robinson Helicopter Company R22, Bozeman, MT, Substantial damage. The CFI was giving instruction to a student on auto rotations. Two 90 degree autorotations were completed successfully, followed by two successful 180 degree… ## Docket (2 files) The files NTSB released with the investigation on January 30, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=95648. 1.1 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40459658&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Photo (Courtesy of FAA) (item 2, .PDF, 1 photo, 114 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40459659&FileExtension=.PDF&FileName=Photo%20(Courtesy%20of%20FAA)-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.