# NTSB WPR13CA068: Robinson R22, N393LE, Logan, UT, December 15, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: December 15, 2012, 13:45 local (20:45 UTC) - Place: Logan, UT - Coordinates: 41.791389, -111.851669 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.7914&lon=-111.8517&mi=10 - Phase of flight: [Emergency descent](https://openairdocs.org/ntsb-phases/600) (OpenAirDocs' grouping) - Defining event: [Autorotation: Loss of lift](https://openairdocs.org/ntsb-events/500) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report April 3, 2013 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 85819 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR13CA068 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/85819/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=85819 - Page: https://openairdocs.org/ntsb/WPR13CA068 ## Probable cause The flight instructor’s delayed remedial action and inadequate supervision during a practice autorotation, which resulted in a failure to maintain adequate main rotor rpm. Contributing to the accident was the wet landing surface. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [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 BETA, 37 cases](https://openairdocs.org/ntsb-findings/01062052/cases.md?model=7640110), [All aircraft, 182 cases](https://openairdocs.org/ntsb-findings/01062052/cases.md) - [Attention/monitoring: monitoring other person](https://openairdocs.org/ntsb-findings/02021535): Personnel issues › Psychological · Instructor/check pilot (probable cause); cases with it: [Robinson Helicopter R22 BETA, 15 cases](https://openairdocs.org/ntsb-findings/02021535/cases.md?model=7640110), [All aircraft, 200 cases](https://openairdocs.org/ntsb-findings/02021535/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 BETA, 35 cases](https://openairdocs.org/ntsb-findings/02041025/cases.md?model=7640110), [All aircraft, 894 cases](https://openairdocs.org/ntsb-findings/02041025/cases.md) - [Runway/land/takeoff/taxi surface: wet surface](https://openairdocs.org/ntsb-findings/03023010): Environmental issues › Physical environment · Contributed to outcome (probable cause); cases with it: [Robinson Helicopter R22 BETA, 1 case](https://openairdocs.org/ntsb-findings/03023010/cases.md?model=7640110), [All aircraft, 141 cases](https://openairdocs.org/ntsb-findings/03023010/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 lift](https://openairdocs.org/ntsb-events/500) (defining event); cases with it: [Robinson Helicopter R22 BETA, 7 cases](https://openairdocs.org/ntsb-events/500/sequence.md?model=7640110), [All aircraft, 252 cases](https://openairdocs.org/ntsb-events/500/sequence.md) - [Landing-flare/touchdown: Abnormal runway contact](https://openairdocs.org/ntsb-events/090); cases with it: [Robinson Helicopter R22 BETA, 5 cases](https://openairdocs.org/ntsb-events/090/sequence.md?model=7640110), [All aircraft, 1,506 cases](https://openairdocs.org/ntsb-events/090/sequence.md) - [Landing: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Robinson Helicopter R22 BETA, 2 cases](https://openairdocs.org/ntsb-events/300/sequence.md?model=7640110), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) ## Analysis During the 180-degree autorotation, the student pilot maintained an airspeed of 65 knots, with rotor rpm in the green. As the student rolled out of the turn about 300 feet above ground level and at 70 knots, the rotor rpm continued to remain in the green. However, before the flare, the rotor rpm began to decay and failed to build as the flare was entered. The flight instructor then took control of the helicopter and immediately rolled on throttle to recover engine power and to maintain rotor rpm, but there was insufficient engine power to recover, and the low rotor rpm light and horn activated. Because power was not available for a full-power-on landing, the flight instructor initiated a full-down autorotation to a taxiway. During the landing, the helicopter skidded across and off the wet taxiway into loose gravel and mud before the left skid dug into the ground, resulting in the helicopter rolling over and coming to rest on its left side. The helicopter sustained substantial damage to its welded frames, firewall, and tail cone. The flight instructor reported no preaccident mechanical or malfunctions or failures with the helicopter or flight controls that would have precluded normal operation. ## Factual narrative During the 180-degree autorotation the student maintained 65 knots with the rotor revolutions per minute (RPM) in the green. As the student rolled out of the turn at about 300 feet above ground level and at 70 knots, the rotor rpm continued to remain in the green. However, prior to the flare the rotor RPM began to decay and failed to build as the flare was entered. The flight instructor then took control of the helicopter and immediately rolled on throttle to recover engine [power] and to maintain [rotor] RPM, but there was insufficient engine power to recover the decayed rotor RPM; this was followed by a low rotor RPM light and horn. As power was not available for a full power on landing, the flight instructor initiated a full down autorotation to a taxiway. During the landing the helicopter skidded across and off the wet taxiway into loose gravel and mud before the left skid dug into the ground. This resulted in the aircraft rolling over and coming to rest on its left side. The helicopter sustained substantial damage to its welded frames, firewall, and tail cone. The flight instructor reported no mechanical malfunctions or failures with the helicopter or flight controls that would have precluded normal operation. ## Aircraft - Registration: [N393LE](https://openairdocs.org/deregistered/N393LE-2013-07-16), registration cancelled 2013-07-16, S/N 4393, built 2008 (OpenAirDocs) - Reported make and model: ROBINSON R22 (BETA) - Registry model: [Robinson Helicopter R22 BETA](https://openairdocs.org/model/robinson-helicopter-r22-beta) (registry code 7640110) (OpenAirDocs) - Registry engine: [Lycoming O-360-J2A](https://openairdocs.org/engine/lycoming-o-360-j2a) (registry code 42314, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 4393 - Airframe hours: 3007 - Engines: Lycoming O-360 145 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Mountain Ridge Helicopters - Registered owner: Mountain Ridge Helicopters - Airworthiness certificate: Standard, Normal - Last inspection: Annual, December 11, 2012, 27 hours before - Departed: LGU, Logan, UT - Destination: LGU, Logan, UT - Airport: LGU, Logan-Cache Airport, runway 35, 9,010 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 23; injuries: none; commercial; instrument ratings: helicopter; medical: class 1, without waivers/limitations; last flight review July 7, 2011; seat: left; flight hours: 651 total, 589 in this make and model, 590 as pilot in command, 129 in the last 90 days, 41 in the last 30 days - Student pilot; age 27; injuries: none; student; medical: class 3, without waivers/limitations; seat: right; flight hours: 62 total, 62 in this make and model, 7 as pilot in command, 62 in the last 90 days, 26 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: 5,000 ft overcast - Temperature: 43 °F, dew point 28 °F - Altimeter: 29.79 inHg - Observed at: LGU ## 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 20121215027449A](https://openairdocs.org/incident/20121215027449A), Dec 15, 2012: Robinson Helicopter R22 BETA, Logan, UT, Substantial damage. Student was in control of aircraft while practicing 180 degree autorotations. Instructor noted that aircraft was in a lower than normal nose down attitude… ## Other investigations on N393LE (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 WPR10LA232](https://openairdocs.org/ntsb/WPR10LA232), May 7, 2010: Robinson Helicopter R22 Beta (N393LE), Mendon, UT, substantial damage. Probable cause: A loss of engine power due to a failure of the magnetos as a result of inadequate maintenance. ## Docket (4 files) The files NTSB released with the investigation on January 16, 2013, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=85819. 2.2 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40384559&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Weather Data (item 2, .PDF, 198 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40384555&FileExtension=.PDF&FileName=Weather%20Data-Master.PDF - FAA Inspector's Reports (item 3, .PDF, 247 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40384556&FileExtension=.PDF&FileName=FAA%20Inspector%27s%20Reports-Redacted.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 4, .PDF, 46 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40384557&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-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.