# NTSB WPR20CA140: Robinson R22, N6703S, Caldwell, ID, April 22, 2020 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: April 22, 2020, 17:00 local (23:00 UTC) - Place: Caldwell, ID - Coordinates: 43.639999, -116.639999 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=43.6400&lon=-116.6400&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 September 21, 2020 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 101256 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR20CA140 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/101256/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=101256 - Page: https://openairdocs.org/ntsb/WPR20CA140 ## Probable cause The flight instructor's failure to set the proper rotor rpm during a practice autorotation, which led to his failure to maintain a proper descent rate and resulted in a hard, bounced landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [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) - [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Instructor/check pilot (probable cause); cases with it: [Robinson Helicopter R22, 4 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=7640102), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md) - [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) ## 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: 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) - [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) ## Analysis The flight instructor reported that, during the instructional flight and while conducting a maximum-glide configuration autorotation, he and the student pilot set the rotor rpm between about 93% and 94%. The instructor began applying aft cyclic to slow the descent rate and to regain rpm; however, the descent rate did not decrease, so he applied more left cyclic to no avail and then increased the throttle. The helicopter landed hard at the most level attitude the instructor could make it, and it then bounced and came to rest. The tailboom was substantially damaged. The Pilot's Operating Manual contained a caution that stated to "increase rotor RPM to 97% minimum when autorotating below 500 ft above ground level." The chief flight instructor reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation. ## Factual narrative The flight instructor reported that during the instructional flight, while conducting autorotation training in a maximum glide configuration, he set the rotor rpm between 93-94%. Aft cyclic was applied to slow down the rate of descent and to regain rpms. The rate of descent did not slow so the throttle was increased, and the helicopter was leveled as it approached the ground. The helicopter subsequently landed hard and bounced once before it came to rest. The tail boom was substantially damaged. A caution in the helicopter's Pilot's Operating Manual states in part to "increase rotor RPM to 97% minimum when autorotating below 500 ft above ground level." The pilot reported that there were no preimpact mechanical malfunctions or failures with the helicopter or engine that would have precluded normal operation. ## Aircraft - Registration: [N6703S](https://openairdocs.org/aircraft/N6703S), registered now, S/N 3621, built 2004 (OpenAirDocs) - Reported make and model: Robinson R22 (BETA) - 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: 3621 - Year built: 2004 - Airframe hours: 7612.2 - Engines: Lycoming O-360 SERIES 180 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, March 19, 2020 - Departed: EUL, Caldwell, ID - Destination: EUL, Caldwell, ID - Flight plan: Company VFR - Airport: EUL, Caldwell Industrial - Equipment: ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 48; injuries: none; commercial, flight instructor; airplane ratings: single-engine land; instrument ratings: airplane, helicopter; medical: class 2, with waivers/limitations; last flight review September 30, 2019; seat: left; restraint: 3-point; flight hours: 644 total, 101 in this make and model, 479 as pilot in command, 101 in the last 90 days, 4 in the last 30 days, 1 in the last 24 hours - Pilot; age 55; injuries: none; private; medical: class 3, without waivers/limitations; last flight review August 21, 2000; seat: right; restraint: 3-point; flight hours: 355 total, 0 in this make and model, 253 as pilot in command, 11 in the last 90 days, 1 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 250° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: 8,500 ft overcast - Temperature: 70 °F, dew point 34 °F - Altimeter: 30.04 inHg - Observed at: KEUL, 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 20200422001109A](https://openairdocs.org/incident/20200422001109A), Apr 22, 2020: Robinson Helicopter Company R22 BETA II, Caldwell, ID, Substantial damage. On the afternoon of April 22, 2020, this flight instructor and a student pilot were on a dual instructional flight in a robertson R-22 helicopter, N6703S.… ## Docket (3 files) The files NTSB released with the investigation on August 21, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=101256. 8.0 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 7.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40486263&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - POH Excerpt (item 2, .PDF, 127 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40486264&FileExtension=.PDF&FileName=POH%20Excerpt-Master.PDF - Damage Picture (item 3, .PDF, 87 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40486265&FileExtension=.PDF&FileName=Damage%20Picture-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.