# NTSB WPR09CA448: Robinson Helicopter R22, N796SH, Irvine, CA, September 15, 2009 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: September 14, 2009, 19:06 local (Sep 15, 2009, 02:06 UTC) - Place: Irvine, CA - Coordinates: 33.680831, -117.70417 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.6808&lon=-117.7042&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 December 29, 2009 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 74738 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR09CA448 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/74738/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=74738 - Page: https://openairdocs.org/ntsb/WPR09CA448 ## Probable cause The flight instructor's failure to maintain an adequate airspeed and his delayed recovery action during the practice autorotation, which resulted in a hard landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Robinson Helicopter R22, 1 case](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=7640102), [All aircraft, 1,681 cases](https://openairdocs.org/ntsb-findings/01062010/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) - [Action: delayed action](https://openairdocs.org/ntsb-findings/02041025): Personnel issues › Action/decision · Instructor/check pilot (probable cause); cases with it: [Robinson Helicopter R22, 7 cases](https://openairdocs.org/ntsb-findings/02041025/cases.md?model=7640102), [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. - [Approach: Simulated/training event](https://openairdocs.org/ntsb-events/600); cases with it: [Robinson Helicopter R22, 3 cases](https://openairdocs.org/ntsb-events/600/sequence.md?model=7640102), [All aircraft, 173 cases](https://openairdocs.org/ntsb-events/600/sequence.md) - [Landing-flare/touchdown: 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 informed the private helicopter pilot under instruction (PUI) that the purpose of the practice autorotation was to demonstrate ways in which to reach a suitable landing zone in the event that an engine failure were to occur in an area with limited landing zones. The intention was to focus on the glide with a power recovery before the need to flare. The instructor entered the autorotation while the PUI observed. The instructor was demonstrating s-turns, beginning with a right 90-degree turn, followed by a left 180-degree turn, and ending with a right 90-degree turn to bring the helicopter back to the original heading. The rotor rpm remained in the green arc or above during the entire maneuver. During the last right 90-degree turn, the helicopter passed through what the instructor estimated to be 200 feet above ground level (agl), where he decided to discontinue the autorotation due to insufficient airspeed (40 KIAS), and a higher than expected rate of descent, which lead to a lower than anticipated height above ground. During the time it took for the instructor to decide to abort the autorotation, the helicopter had descended to approximately 20-30 feet agl. The instructor initiated a flare, and he focused on keeping the skids level, but the right skid hit a dirt ledge adjacent to the proposed landing spot that was approximately 6 feet higher than the surface of the intended landing zone. As the right skid impacted the ground, the helicopter pitched forward, and the nose impacted the ground. The pilot reported no mechanical failures or malfunctions at the time of the accident. ## Factual narrative The flight instructor informed the private helicopter pilot under instruction (PUI) that the purpose of the practice autorotation was to demonstrate ways in which to reach a suitable landing zone in the event that an engine failure were to occur in an area with limited landing zones. The intention was to focus on the glide with a power recovery before the need to flare. The instructor entered the autorotation while the PUI observed, but was not on the controls. The instructor was demonstrating s-turns, beginning with a right 90-degree turn, followed by a left 180-degree turn, and ending with a right 90-degree turn to bring the helicopter back to the original heading. The rpm remained in the green arc or above during the entire maneuver. During the last right 90-degree turn, the helicopter passed through what the instructor estimated to be 200 feet above ground level (agl), where he decided to discontinue the autorotation due to insufficient airspeed (40 KIAS), and a higher than expected rate of descent, which lead to a lower than anticipated height above ground. During the time it took for the instructor to decide to abort the autorotation, the helicopter had descended to approximately 20-30 feet agl. The instructor initiated a flare, and he focused on keeping the skids level, but the right skid hit a dirt ledge adjacent to the proposed landing spot that was approximately 6 feet higher than the surface of the intended landing zone. As the right skid impacted the ground, the helicopter pitched forward, and the nose impacted the ground. The pilot reported no mechanical failures or malfunctions at the time of the accident. ## Aircraft - Registration: [N796SH](https://openairdocs.org/deregistered/N796SH-2012-10-03), registration cancelled 2012-10-03, S/N 3731, built 2004 (OpenAirDocs) - Reported make and model: ROBINSON HELICOPTER COMPANY R22 - 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: 3731 - Airframe hours: 4054 - Engines: LYCOMING O-360 SERIES 180 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Nu Vista Aviation LLC - Registered owner: Nu Vista Aviation LLC - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, August 29, 2009, 50 hours before - Departed: CNO, Chino, CA - Destination: CNO, Chino, CA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 34; injuries: none; flight instructor, commercial; instrument ratings: helicopter; medical: class 1, with waivers/limitations; last flight review April 7, 2009; seat: left; flight hours: 460 total, 405 in this make and model, 395 as pilot in command, 36 in the last 90 days, 10 in the last 30 days, 1 in the last 24 hours - Pilot; age 23; injuries: none; private; medical: class 1, with waivers/limitations; last flight review July 25, 2009; seat: right; flight hours: 94 total, 94 in this make and model, 45 as pilot in command, 61 in the last 90 days, 25 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 250° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 68 °F, dew point 57 °F - Altimeter: 29.95 inHg - Observed at: SNA, 8 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 20090914018089A](https://openairdocs.org/incident/20090914018089A), Sep 14, 2009: Robsin R22, El Toro, CA, Destroyed. While demonstrating an autorotation glide to a student, the pilot/cfi allowed the rate of descent to become excessive which caused the aircraft to descend… ## Docket (1 files) The files NTSB released with the investigation on October 23, 2009, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=74738. 405 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 405 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40320118&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. --- 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.