# NTSB CEN14LA313: Robinson R22 - Beta, N784SH, Moscow Mills, MO, June 19, 2014 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: June 19, 2014, 10:30 local (15:30 UTC) - Place: Moscow Mills, MO - Coordinates: 38.940834, -90.910575 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=38.9408&lon=-90.9106&mi=10 - Phase of flight: [Emergency descent](https://openairdocs.org/ntsb-phases/600) (OpenAirDocs' grouping) - Defining event: [Autorotation: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report June 1, 2015 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Robinson Helicopter Company, Federal Aviation Administration - NTSB case key (mKey): 89522 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN14LA313 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/89522/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=89522 - Page: https://openairdocs.org/ntsb/CEN14LA313 ## Probable cause The flight instructor’s delayed remedial action to correct the student pilot’s use of an excessive descent rate during a practice autorotation, which resulted in a hard landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [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) - [Performance/control parameters: descent rate](https://openairdocs.org/ntsb-findings/01062037): Aircraft › Aircraft oper/perf/capability · Not specified (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) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Autorotation: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Robinson Helicopter R22, 9 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=7640102), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/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) - [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Robinson Helicopter R22, 9 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7640102), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) - [Landing: Hard landing](https://openairdocs.org/ntsb-events/092); 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, about 1 hour into the instructional flight, the student pilot began to perform a practice 180-degree autorotation. While the helicopter was about 100 ft above ground level, the flight instructor noted that the helicopter was descending at an excessive rate, so he took the flight controls and added power in an attempt to flare the helicopter before it touched down. However, the flight instructor was unable to arrest the descent rate, and the helicopter impacted the ground hard. Examination of the helicopter revealed no mechanical anomalies that would have precluded normal operation. ## Factual narrative On June 19, 2014, at 1030 central daylight time, a Robinson Helicopter Company R-22 Beta, N784SH, impacted terrain during a practice autorotation at Greensfield Airport (M71), Moscow Mills, Missouri. The helicopter sustained substantial damage. The flight instructor and student pilot sustained minor injuries. The helicopter was operated by Helicopter Services and Technologies, LLC (DBA HeliSat) under 14 CFR Part 91 as an instructional flight. Visual meteorological conditions prevailed at the time of the accident. The flight was not operating on a flight plan and departed from the operator's facility in Moscow Mills, Missouri, about 0930 on a local flight The flight instructor stated that training flight began about 0930 with normal takeoffs, landings, and autorotations at M71. At approximately 10:30, the student pilot began to perform a 180-degree autorotation. While turning towards the runway during a 180-degree autorotation, with the RPM just above the green arc and with an airspeed of 65 knots, helicopter began to "fall" through about 100 feet above ground level. The instructor took the flight controls and tried to roll on the throttle and flare the helicopter before it touched down onto the ground. Examination of the helicopter by a Federal Aviation Administration maintenance inspector revealed no mechanical anomalies that would have precluded normal operation. The sprag clutch was removed and examined at Robinson Helicopter Company under the supervision of personnel from the Los Angeles Aircraft Certification Office and Manufacture Inspection District Office. The report of the sprag clutch examination (A166-1 clutch shaft serial number 9795, A188-2 sprag assembly serial number 10453, and the A184-1 support bearing) stated, in part: The sheave was rotated by hand in the direction of normal rotation, the clutch shaft moved with the sheave, as the sheave was rotated opposite the direction of normal rotation, the sheave freewheeled on the shaft. A slight roughness was felt when rotating the shaft. Both yokes and support bearing were removed. The forward retainer plate was removed and the oil was drained from the assembly. The oil appeared black but still had a red tint to it. The oil did not smell burnt. Approximately 9 milliliters was recovered from the assembly (typical clutch assembly contains approximately 17 milliliters). The recovered oil was scanned with a magnet and a small, thin metallic chip was recovered. The bearings were pressed out of the sheave and off of the shaft and the sprag assembly removed. Both bearings had rough spots when rotated by hand. Both bearings were flushed with solvent and afterward the bearings rotated smoothly. The flushing solvent from both bearings was scanned with a magnet and several very small, metallic slivers were recovered. The bearing contact surface of the inner and outer races were visually examined, no discoloration or damage was noted. The inner contact surface of several sprags of the spragassembly had small areas of the surface plating (proprietary to Formsprag) gouged/chipped away with one sprag having a larger area damaged. The outer surface of the sprags appeared normal. The sprag surface of the clutch shaft and the sheave had several scuff marks that appeared to match the size and spacing of the sprags with two areas on the shaft that match the shape of the more damaged sprag. There was no other rotational scoring of the sprag surfaces. The diameter of the sprag surface on the clutch shaft was measured and verified to be within production specifications. ## Aircraft - Registration: [N784SH](https://openairdocs.org/deregistered/N784SH-2018-03-06), registration cancelled 2018-03-06, S/N 3622, 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: 3622 - Airframe hours: 111 - Engines: Lycoming O-360-J2A 145 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Helicopter Services and Technologies, LLC, doing business as HeliSat - Registered owner: Eric A Sptizer LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 15, 2014 - Departed: Moscow Mills, MO - Destination: M71, Moscow Mills, MO - Airport: M71, Greensfield Airport, runway 27, 3,227 × 50 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 32; injuries: minor; commercial, flight instructor; instrument ratings: helicopter; medical: class 1, with waivers/limitations; last flight review June 6, 2013; seat: left; restraint: 3-point; flight hours: 1,318 total, 558 in this make and model, 1,244 as pilot in command, 63 in the last 90 days, 20 in the last 30 days, 1 in the last 24 hours - Student pilot; age 27; injuries: minor; medical: class 1, without waivers/limitations; seat: right; restraint: 3-point; flight hours: 71 total, 24 in this make and model, 1 as pilot in command, 7 in the last 90 days, 3 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 230° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 84 °F, dew point 72 °F - Altimeter: 30.04 inHg - Observed at: FYG, 19 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 20140619012749A](https://openairdocs.org/incident/20140619012749A), Jun 19, 2014: Robinson Helicopter Company R22, Moscow Mills, MO, Substantial damage. Flight instructor was giving student pilot instruction in the 180-autorotation manuever. At 100 feet AGL the flight instructor reported a sinking feeling and… ## Docket (4 files) The files NTSB released with the investigation on April 16, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=89522. 3.4 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40425137&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - FAA Inspector Statement (item 2, .PDF, 594 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40425138&FileExtension=.PDF&FileName=FAA%20Inspector%20Statement-Redacted.PDF - Component Examination (item 3, .PDF, 522 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40425143&FileExtension=.PDF&FileName=Component%20Examination-Redacted.PDF - Certification of Party Representative (item 4, .PDF, 367 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40425140&FileExtension=.PDF&FileName=Certification%20of%20Party%20Representative-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.