# NTSB GAA17CA251: Bender Joseph KIT Rotoway, N164JB, Wheatland, WY, April 30, 2017 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: April 30, 2017, 17:15 local (23:15 UTC) - Place: Wheatland, WY - Coordinates: 42.077499, -105.057777 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=42.0775&lon=-105.0578&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-flare/touchdown: Dynamic rollover](https://openairdocs.org/ntsb-events/231) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report July 20, 2017 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 95085 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA17CA251 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/95085/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=95085 - Page: https://openairdocs.org/ntsb/GAA17CA251 ## Probable cause The pilot's decision to operate the helicopter in gusting wind and high-density altitude conditions and his positioning of the helicopter such that it resulted in a right quartering tailwind, which resulted in a loss of helicopter control due to a loss of tail rotor effectiveness. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Bender Joseph KIT ROTOWAY, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=05617T0), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Bender Joseph KIT ROTOWAY, 1 case](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=05617T0), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Temp/humidity/pressure: high density altitude](https://openairdocs.org/ntsb-findings/03031020): Environmental issues › Conditions/weather/phenomena · Decision related to condition (probable cause); cases with it: [Bender Joseph KIT ROTOWAY, 1 case](https://openairdocs.org/ntsb-findings/03031020/cases.md?model=05617T0), [All aircraft, 278 cases](https://openairdocs.org/ntsb-findings/03031020/cases.md) - [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: [Bender Joseph KIT ROTOWAY, 1 case](https://openairdocs.org/ntsb-findings/01062052/cases.md?model=05617T0), [All aircraft, 182 cases](https://openairdocs.org/ntsb-findings/01062052/cases.md) - [Wind: gusts](https://openairdocs.org/ntsb-findings/03034045): Environmental issues › Conditions/weather/phenomena · Decision related to condition (probable cause); cases with it: [Bender Joseph KIT ROTOWAY, 1 case](https://openairdocs.org/ntsb-findings/03034045/cases.md?model=05617T0), [All aircraft, 1,199 cases](https://openairdocs.org/ntsb-findings/03034045/cases.md) - [Wind: tailwind](https://openairdocs.org/ntsb-findings/03034015): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Bender Joseph KIT ROTOWAY, 1 case](https://openairdocs.org/ntsb-findings/03034015/cases.md?model=05617T0), [All aircraft, 594 cases](https://openairdocs.org/ntsb-findings/03034015/cases.md) - [Wind: gusts](https://openairdocs.org/ntsb-findings/03034045): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Bender Joseph KIT ROTOWAY, 1 case](https://openairdocs.org/ntsb-findings/03034045/cases.md?model=05617T0), [All aircraft, 1,199 cases](https://openairdocs.org/ntsb-findings/03034045/cases.md) - [Temp/humidity/pressure: high density altitude](https://openairdocs.org/ntsb-findings/03031020): Environmental issues › Conditions/weather/phenomena · Decision related to condition; cases with it: [Bender Joseph KIT ROTOWAY, 1 case](https://openairdocs.org/ntsb-findings/03031020/cases.md?model=05617T0), [All aircraft, 278 cases](https://openairdocs.org/ntsb-findings/03031020/cases.md) - [Object/animal/substance: hidden/submerged object](https://openairdocs.org/ntsb-findings/03022052): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Bender Joseph KIT ROTOWAY, 1 case](https://openairdocs.org/ntsb-findings/03022052/cases.md?model=05617T0), [All aircraft, 36 cases](https://openairdocs.org/ntsb-findings/03022052/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Bender Joseph KIT ROTOWAY, 1 case](https://openairdocs.org/ntsb-events/400/sequence.md?model=05617T0), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md) - [Landing-flare/touchdown: Loss of tail rotor effectiveness](https://openairdocs.org/ntsb-events/242); cases with it: [Bender Joseph KIT ROTOWAY, 1 case](https://openairdocs.org/ntsb-events/242/sequence.md?model=05617T0), [All aircraft, 100 cases](https://openairdocs.org/ntsb-events/242/sequence.md) - [Landing-flare/touchdown: Dynamic rollover](https://openairdocs.org/ntsb-events/231) (defining event); cases with it: [Bender Joseph KIT ROTOWAY, 1 case](https://openairdocs.org/ntsb-events/231/sequence.md?model=05617T0), [All aircraft, 161 cases](https://openairdocs.org/ntsb-events/231/sequence.md) - [Landing-flare/touchdown: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Bender Joseph KIT ROTOWAY, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=05617T0), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot of the experimental amateur-built helicopter, which had a clockwise rotating main rotor blade, reported that he took off from private property with a right crosswind. He added that, when the helicopter reached 20 to 30 knots, about 50 ft above the ground, he turned southwest, which resulted in a right quartering tailwind. He further added that, as he made the turn, he applied right antitorque pedal, but "nothing was there." The pilot reported that he subsequently decided to "set it down" in a field ahead and that, about 3 to 5 ft above the ground, the "tail started to come around counter-clockwise." During the touchdown, the right skid caught on a hidden car muffler, and the helicopter rolled onto its right side and impacted terrain. During a postaccident interview, the pilot reported that he "lost tail rotor effectiveness," and he encountered "too much wind for this aircraft [helicopter]." The main rotor and tailboom sustained substantial damage. The pilot reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation. The pilot reported that the wind was from the north and about 15 knots. The nearest automated weather observation station (AWOS), 41 nautical miles (nm) from the accident site, recorded that, about the time of the accident, the wind was from 350° at 14 knots, gusting to 26 knots. About 20 minutes before the accident, the AWOS recorded a peak wind from 340° at 30 knots. The density altitude at the AWOS location was 5,332 ft. The Federal Aviation Administration Helicopter Flying Handbook stated, in part: "Loss of tail rotor effectiveness (LTE) or an unanticipated yaw is defined as an uncommanded, rapid yaw towards the advancing blade which does not subside of its own accord. It can result in the loss of the aircraft if left unchecked." The handbook further stated, in part: "At higher altitudes where the air is thinner, tail rotor thrust and efficiency are reduced. Because of the high density altitude, powerplants may be much slower to respond to power changes. When operating at high altitudes and high gross weights, especially while hovering, the tail rotor thrust may not be sufficient to maintain directional control, and LTE can occur." It is likely that the high-density altitude and the pilot's positioning of the helicopter such that it resulted in a right quartering tailwind reduced the tail rotor effectiveness of the helicopter and contributed to the pilot's inability to maintain helicopter control during the hover to landing. ## Factual narrative The pilot of an experimental amateur-built helicopter, which had a clockwise rotating main rotor blade, reported that he took off from private property with a right crosswind. He added that when the helicopter reached 20-30 knots, about 50 ft. above ground, he turned southwest, which resulted in a right quartering tailwind. He further added that as he made the turn, he applied right anti-torque pedal, but "nothing was there." Subsequently, the pilot reported that he decided to "set it down" in a field ahead, and about 3-5 ft. above the ground the "tail started to come around counter-clockwise." During the touchdown, the right skid caught on a hidden car muffler and the helicopter rolled onto its right side and impacted terrain. During a postaccident interview, the pilot reported that he "lost tail rotor effectiveness," and he encountered "too much wind for this aircraft [helicopter]." The main rotor and tail boom sustained substantial damage. The pilot reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation. In an interview with the National Transportation Safety Board investigator-in-charge, the pilot reported that the wind was from the north, about 15 knots. An automated weather observation station (AWOS), 41 nautical miles (NM) from the accident site, about the time of the accident, recorded wind 350° at 14 knots, gusting to 26 knots. The AWOS recorded a peak wind, about 20 minutes before the accident, 340° at 30 knots. The density altitude, at the nearest airport with a recorded AWOS, 41 NM from the accident site, was 5,332 ft. The Federal Aviation Administration Helicopter Flying Handbook stated in part: Loss of tail rotor effectiveness (LTE) or an unanticipated yaw is defined as an uncommanded, rapid yaw towards the advancing blade which does not subside of its own accord. It can result in the loss of the aircraft if left unchecked." The handbook further stated in part: "At higher altitudes where the air is thinner, tail rotor thrust and efficiency are reduced. Because of the high density altitude, powerplants may be much slower to respond to power changes. When operating at high altitudes and high gross weights, especially while hovering, the tail rotor thrust may not be sufficient to maintain directional control, and LTE can occur." ## Aircraft - Registration: [N164JB](https://openairdocs.org/deregistered/N164JB-2022-04-08), registration cancelled 2022-04-08, S/N 6763, built 2004 (OpenAirDocs) - Reported make and model: BENDER JOSEPH KIT ROTOWAY (NO SERIES) - Registry model: [Bender Joseph KIT ROTOWAY](https://openairdocs.org/model/bender-joseph-kit-rotoway) (registry code 05617T0) (OpenAirDocs) - Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Helicopter, amateur-built - Serial number: 6763 - Year built: 2004 - Airframe hours: 298 - Engines: Rotorway 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, April 22, 2017 - Departed: Wheatland, WY - Destination: Wheatland, WY - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 53; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review December 30, 2016; seat: left; flight hours: 1,068.9 total, 22.7 in this make and model, 1,002 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 350° at 14 knots, gusting 26 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 59 °F, dew point 16 °F - Altimeter: 29.84 inHg - Observed at: KTOR, 41 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 20170430003409A](https://openairdocs.org/incident/20170430003409A), Apr 30, 2017: Rotoway KIT ROTOWAY, Wheatland, WY, Substantial damage. On 4/30/2017 at 1715 MDT, a xxxxxxxx, N164JB, impacted the ground near Phifer Airfield (ean). There was xxx POB onboard with no injuries. The aircraft was… ## Docket (4 files) The files NTSB released with the investigation on June 27, 2017, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=95085. 1.9 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 478 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40453756&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Record of Conversation (Pilot in Command) (item 2, .PDF, 63 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40453757&FileExtension=.PDF&FileName=Record%20of%20Conversation%20(Pilot%20in%20Command)-Master.PDF - Accident Photos (Courtesy of FAA) (item 3, .PDF, 2 photos, 401 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40453758&FileExtension=.PDF&FileName=Accident%20Photos%20(Courtesy%20of%20FAA)-Master.PDF - FAA Helicopter Flying Handbook LTE (item 4, .PDF, 995 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40453759&FileExtension=.PDF&FileName=FAA%20Helicopter%20Flying%20Handbook%20LTE-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.