# NTSB ERA12CA357: Hughes TH-55, N74914, Pittsfield, PA, May 19, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: May 19, 2012, 17:17 local (21:17 UTC) - Place: Pittsfield, PA - Coordinates: 41.826389, -79.361389 - Nearby events: https://openairdocs.org/map.md?lat=41.8264&lon=-79.3614&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report March 13, 2013 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA Allegheny FSDO - NTSB case key (mKey): 83736 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA12CA357 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/83736/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=83736 - Page: https://openairdocs.org/ntsb/ERA12CA357 ## Probable cause The student pilot's failure to maintain helicopter control during an encounter with loss of tail rotor effectiveness. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Tail rotor](https://openairdocs.org/ntsb-findings/01046400): Aircraft › Aircraft propeller/rotor · Related operating info (probable cause); cases with it: [Hughes TH-55, 1 case](https://openairdocs.org/ntsb-findings/01046400/cases.md?model=4471002), [All aircraft, 23 cases](https://openairdocs.org/ntsb-findings/01046400/cases.md) - [Action: incorrect action selection](https://openairdocs.org/ntsb-findings/02041010): Personnel issues › Action/decision · Student/instructed pilot (probable cause); cases with it: [Hughes TH-55, 1 case](https://openairdocs.org/ntsb-findings/02041010/cases.md?model=4471002), [All aircraft, 397 cases](https://openairdocs.org/ntsb-findings/02041010/cases.md) - [Experience/qualifications: total experience](https://openairdocs.org/ntsb-findings/02031015): Personnel issues › Experience/knowledge · Student/instructed pilot; cases with it: [Hughes TH-55, 1 case](https://openairdocs.org/ntsb-findings/02031015/cases.md?model=4471002), [All aircraft, 126 cases](https://openairdocs.org/ntsb-findings/02031015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach: Loss of tail rotor effectiveness](https://openairdocs.org/ntsb-events/242); cases with it: [Hughes TH-55, 1 case](https://openairdocs.org/ntsb-events/242/sequence.md?model=4471002), [All aircraft, 100 cases](https://openairdocs.org/ntsb-events/242/sequence.md) - [Approach: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Hughes TH-55, 1 case](https://openairdocs.org/ntsb-events/060/sequence.md?model=4471002), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) - [Approach: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Hughes TH-55, 2 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=4471002), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Approach: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Hughes TH-55, 2 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=4471002), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis According to the student pilot, who had about 36 hours total flight time, he had completed a solo flight earlier in the day that included seven takeoffs and landings. After refueling, he completed a local flight and returned to the departure airport, where he initiated an approach that terminated "perfectly" in a normal hover. However, the helicopter then "started spinning to the right," and the spin could not be arrested with full application of left pedal. The pilot stated that he then increased collective pitch and the corresponding increase in engine power aggravated the spin. He then attempted a hovering autorotation, but the helicopter landed hard, rolled over on to its side, and was substantially damaged. A witness described the helicopter as it approached "flying somewhat erratically" about 40 feet above the runway. The helicopter was "twisting" to the left and right as it hovered "shakily" closer to the runway. The helicopter noise increased, the nose pitched up, the main rotors struck the ground, and the helicopter came to rest on its side. A detailed examination of the wreckage revealed no preimpact mechanical malfunctions or anomalies that would have precluded normal operation. A Federal Aviation Administration advisory circular stated that loss of tail rotor effectiveness (LTE) is a critical, low-speed aerodynamic flight characteristic which could result in an uncommanded rapid yaw rate which does not subside of its own accord and, if not corrected, could result in the loss of aircraft control. Further, any maneuver that required the pilot to operate in a high-power, low-airspeed environment with a left crosswind or tailwind would create an environment where unanticipated right yaw may occur. The nearest weather reporting station, which was located about 19 nautical miles from the accident site, recorded a 7-knot, left quartering tailwind for the landing on runway 9. ## Factual narrative According to the student pilot, he had completed a solo flight earlier in the day that included 7 takeoffs and landings. After refueling, he completed a local flight and returned to the departure airport where he initiated an approach to the runway with a 7-knot, left quartering tailwind. The approach terminated "perfectly" to a normal hover. According to the pilot, the helicopter "started spinning to the right" and the spin could not be arrested with full application of left pedal. The pilot stated he then increased collective pitch and the corresponding increase in engine power aggravated the spin. He then attempted a hovering autorotation, but the helicopter landed hard, rolled over on to its side, and was substantially damaged. A witness described the helicopter as it approached "flying somewhat erratically" about 40 feet above the runway. The helicopter was "twisting" to the left and right as it hovered "shakily" closer to the runway. The helicopter noise increased, the nose pitched up, the main rotors struck the ground, and the helicopter came to rest on its side. An FAA advisory circular stated that loss of tail rotor effectiveness (LTE) was a critical, low-speed aerodynamic flight characteristic which could result in an uncommanded rapid yaw rate which does not subside of its own accord and, if not corrected, could result in the loss of aircraft control. Further, any maneuver which required the pilot to operate in a high-power, low-airspeed environment with a left crosswind or tailwind created an environment where unanticipated right yaw may occur. The pilot reported 40 total hours of flight experience, all of which was in the accident helicopter make and model. A detailed examination of the wreckage by Federal Aviation Administration inspectors revealed no pre-impact mechanical anomalies. ## Aircraft - Registration: [N74914](https://openairdocs.org/aircraft/N74914), registered now, S/N 67-15442, built 1968 (OpenAirDocs) - Reported make and model: HUGHES TH-55 - Registry model: [Hughes TH-55](https://openairdocs.org/model/hughes-th-55) (registry code 4471002) (OpenAirDocs) - Registry engine: [Lycoming HIO-360 series](https://openairdocs.org/engine/lycoming-hio-360-series) (registry code 41524, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 67-15442 - Airframe hours: 12905 - Engines: LYCOMING HIO-360 SER 205 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Steven Tachoir - Registered owner: Steven And Gail Tachoir - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 8, 2011 - Departed: P15, Pittsfield, PA - Destination: P15, Pittsfield, PA - Airport: P15, Brokeenstraw Airport, runway 09, 2,665 × 100 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Student pilot; age 52; injuries: none; student; medical: class 2, with waivers/limitations; seat: right; flight hours: 36 total, 36 in this make and model, 6 as pilot in command, 16 in the last 90 days, 13 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 330° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 46 °F - Altimeter: 30.17 inHg - Observed at: KJHW, 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 20120519011819A](https://openairdocs.org/incident/20120519011819A), May 19, 2012: Hughes TH-55, Pittsfield, PA, Substantial damage. On approach to land @ approximately 40 feet, the solo student pilot attempted to recover from low rotor RPM. The student pilot over corrected with throttle… ## Other investigations on N74914 (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 ATL98LA021](https://openairdocs.org/ntsb/ATL98LA021), Dec 9, 1997: Hughes TH-55 (N74914), Bushnell, FL, substantial damage. Probable cause: The pilot's failure to maintain clearance from the trees during a hover. A factor was the pilot's diverted attention. ## Docket (7 files) The files NTSB released with the investigation on January 25, 2013, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=83736. 8.9 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40368917&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Pilot Statment (Courtesy of FAA) (item 2, .PDF, 393 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40369055&FileExtension=.PDF&FileName=Pilot%20Statment%20(Courtesy%20of%20FAA)-Redacted.PDF - Witness Statment (Courtesy of FAA) (item 3, .PDF, 231 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40369056&FileExtension=.PDF&FileName=Witness%20Statment%20(Courtesy%20of%20FAA)-Redacted.PDF - FAA Inspectors Statements (item 4, .PDF, 177 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40369058&FileExtension=.PDF&FileName=FAA%20Inspectors%20Statements-Redacted.PDF - Pittsfield (JHW) Meteorological Observations (item 5, .PDF, 118 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40368918&FileExtension=.PDF&FileName=Pittsfield%20(JHW)%20Meteorological%20Observations-Master.PDF - Photo 1 - Overview Of Wreckage (Courtesy of FAA) (item 6, .PDF, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40369061&FileExtension=.PDF&FileName=Photo%201%20-%20Overview%20Of%20Wreckage%20(Courtesy%20of%20FAA)-Master.PDF - Photo 2 - View of Tailboom (Courtesy of FAA) (item 7, .PDF, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40369064&FileExtension=.PDF&FileName=Photo%202%20-%20View%20of%20Tailboom%20(Courtesy%20of%20FAA)-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.