# NTSB CEN17LA099: Robinson R22 Beta, N522KC, Asherton, TX, October 28, 2016 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: October 28, 2016, 10:00 local (15:00 UTC) - Place: Asherton, TX - Coordinates: 28.433332, -99.76667 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=28.4333&lon=-99.7667&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report November 6, 2018 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Federal Aviation Administration; San Antonio FSDO - NTSB case key (mKey): 94687 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN17LA099 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/94687/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=94687 - Page: https://openairdocs.org/ntsb/CEN17LA099 ## Probable cause The partial loss of engine power due to the failure of the magneto's internal timing during low-altitude maneuvering. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Ignition system: magneto/distributor](https://openairdocs.org/ntsb-findings/01057414): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Robinson Helicopter R22 BETA, 2 cases](https://openairdocs.org/ntsb-findings/01057414/cases.md?model=7640110), [All aircraft, 101 cases](https://openairdocs.org/ntsb-findings/01057414/cases.md) - [Performance/control parameters: prop/rotor parameters](https://openairdocs.org/ntsb-findings/01062052): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (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) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-low-alt flying: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340); cases with it: [Robinson Helicopter R22 BETA, 5 cases](https://openairdocs.org/ntsb-events/340/sequence.md?model=7640110), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Maneuvering-low-alt flying: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Robinson Helicopter R22 BETA, 11 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=7640110), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Robinson Helicopter R22 BETA, 23 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=7640110), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The helicopter experienced a loss in rotor rpm while maneuvering during a low-level wildlife survey. The commercial pilot then performed a forced landing to a field. Postaccident examination of the helicopter revealed that one of the engine magnetos had an internal timing, efficiency gap failure, which would have resulted in improper engine ignition timing and loss of engine power/rpm. Examination also revealed that the magneto distributer gear was loose and that the distributer gear bushing was flapping around. ## Factual narrative On October 28, 2016, at 1000 central daylight time, a Robinson Helicopter R22 Beta, N522KC, impacted terrain during a forced landing after a partial loss of engine power near Asherton, Texas. The helicopter sustained substantial damage. The pilot was uninjured. The helicopter was registered to Rotor Spec Aviation LLC and operated by the pilot under Title 14 Code of Federal Regulations Part 91 as an aerial wildlife survey flight that was not operating on a flight plan. Day visual meteorological conditions prevailed at the time of the accident. The local flight originated from Asherton, Texas at time unknown. A National Transportation Safety Board (NTSB) Pilot/Operator Aircraft Accident/Incident Report was not received from the pilot. According to a Federal Aviation Administration inspector, the helicopter experienced a loss in rotor rpm while maneuvering at low level during a wildlife survey. The pilot then performed a forced landing to a field. Post-accident examination of the helicopter revealed a failure of one of the engine magnetos. The wreckage had been moved and sold by the operator without the knowledge of the Federal Aviation Administration inspector and the NTSB. The NTSB Investigator-in-Charge located the engine at an engine maintenance facility whose representative stated that he examined the engine magnetos and one of the magnetos, Bendix model number S4LSC-200, part number 10-600614-1, serial number J229358E, had an internal timing, efficiency gap (E-gap) failure. He said the magneto distributer gear was loose, and the distributer gear bushing was "flapping" around. ## Aircraft - Registration: [N522KC](https://openairdocs.org/deregistered/N522KC-2018-06-27), registration cancelled 2018-06-27, S/N 3939, built 2005 (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 series](https://openairdocs.org/engine/lycoming-o-360-series) (registry code 41575, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 3939 - Year built: 2005 - Airframe hours: 1803 - Engines: Lycoming O-360-J2A reciprocating - Damage: Substantial damage - Flight: Aerial observation, Part 91 - Operator: Pilot - Registered owner: Pat Morris - Airworthiness certificate: Standard, Normal - Departed: Asherton, TX - Destination: Asherton, TX ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 63; injuries: none; commercial; medical: unknown; flight hours: 10,500 total, 10,000 in this make and model, 200 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 80° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 73 °F, dew point 61 °F - Altimeter: 30.21 inHg - Observed at: COT, 25 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 20161028024899A](https://openairdocs.org/incident/20161028024899A), Oct 28, 2016: Robinson Helicopter R22 BETA, Asherton, TX, Substantial damage. While maneuvering at low level the helicopter experienced a reduction of rotor RPM. Aircraft impacted the ground remaining upright with substantial damage to… ## Docket (3 files) The files NTSB released with the investigation on October 2, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=94687. 181 KB in all. - Request for NTSB Accident Report Form 6120 (item 1, .PDF, 73 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40467163&FileExtension=.PDF&FileName=Request%20for%20NTSB%20Accident%20Report%20Form%206120-Master.PDF - Record of Correspondence - FAA (item 2, .PDF, 53 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40467164&FileExtension=.PDF&FileName=Record%20of%20Correspondence%20-%20FAA-Master.PDF - Record of Conversation - Repair Station (item 3, .PDF, 56 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40467165&FileExtension=.PDF&FileName=Record%20of%20Conversation%20-%20Repair%20Station-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.