# NTSB ERA10LA023: Mcdonnell Douglas Helicopter 369E, N502SL, Winnsboro, SC, October 19, 2009 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: October 19, 2009, 14:30 local (18:30 UTC) - Place: Winnsboro, SC - Coordinates: 34.315277, -81.108612 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.3153&lon=-81.1086&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-flare/touchdown: Hard landing](https://openairdocs.org/ntsb-events/092) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report May 28, 2010 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO, Rolls-Royce - NTSB case key (mKey): 74931 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA10LA023 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/74931/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=74931 - Page: https://openairdocs.org/ntsb/ERA10LA023 ## Probable cause The flight instructor's failure to monitor the simulated emergency procedure, resulting in a hard landing. Contributing to the accident was the intentional throttle application by one of the flightcrew. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine controls: power lever](https://openairdocs.org/ntsb-findings/01057603): Aircraft › Aircraft power plant · Incorrect use/operation (probable cause); cases with it: [Mcdonnell Douglas Helicopter 369E, 1 case](https://openairdocs.org/ntsb-findings/01057603/cases.md?model=3027369), [All aircraft, 95 cases](https://openairdocs.org/ntsb-findings/01057603/cases.md) - [Attention/monitoring: task monitoring/vigilance](https://openairdocs.org/ntsb-findings/02021520): Personnel issues › Psychological · Instructor/check pilot (probable cause); cases with it: [Mcdonnell Douglas Helicopter 369E, 2 cases](https://openairdocs.org/ntsb-findings/02021520/cases.md?model=3027369), [All aircraft, 330 cases](https://openairdocs.org/ntsb-findings/02021520/cases.md) - [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Flight crew (probable cause); cases with it: [Mcdonnell Douglas Helicopter 369E, 1 case](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=3027369), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-hover: Simulated/training event](https://openairdocs.org/ntsb-events/600); cases with it: [Mcdonnell Douglas Helicopter 369E, 1 case](https://openairdocs.org/ntsb-events/600/sequence.md?model=3027369), [All aircraft, 173 cases](https://openairdocs.org/ntsb-events/600/sequence.md) - [Landing-flare/touchdown: Hard landing](https://openairdocs.org/ntsb-events/092) (defining event); cases with it: [Mcdonnell Douglas Helicopter 369E, 8 cases](https://openairdocs.org/ntsb-events/092/sequence.md?model=3027369), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis During an instructional flight while in a three-foot hover, the certified flight instructor (CFI) applied right anti-torque pedal input with the intention of simulating loss of tail rotor thrust while in a hover. The student correctly reduced throttle and both occupants agree that the helicopter contacted the ground. While neither occupant agrees as to who applied throttle control, throttle control input was applied and the helicopter became airborne with slow main rotor rpm. The CFI took the controls and attempted to cushion the landing, but the helicopter landed hard. There were no reported preimpact failures or malfunctions. After the accident the engine was placed in a test cell and operated to full power with no evidence of failure or malfunction. ## Factual narrative On October 19, 2009, about 1430 eastern daylight time, a McDonnell-Douglas 369E helicopter, N502SL, registered to South Carolina Law Enforcement Division (SLED), was landed hard at the Fairfield County Airport (FDW), Winnsboro, South Carolina. Visual meteorological conditions prevailed at the time and no flight plan was filed for the 14 Code of Federal Regulations (CFR) Part 91 instructional flight. The helicopter was substantially damaged and the certified flight instructor (CFI) and rotorcraft- rated student (student) were not injured. The flight originated from the SLED Heliport (2SC6), Columbia, South Carolina, about 1400. The student stated that after departure the flight proceeded to FDW where he executed two normal approaches. After the second, he hover taxied to a grassy area south of runway 04/22, where he and the CFI noted the wind direction and discussed the next maneuver to be performed which was loss of tail rotor thrust while in a hover. The briefing before the maneuver included the proper recovery procedure which was to slowly reduce throttle control. While in a three foot hover the CFI announced that he was initiating the loss of tail rotor thrust and the helicopter began slowly yawing to the right. The student initiated recovery by reducing throttle and while in a two foot hover the CFI instructed him to regain the entry altitude of three feet. The student increased collective control which reduced rotor rpm and induced another right yaw. He then reduced throttle which caused the rotor rpm to deteriorate further resulting in the helicopter descending. He increased collective control to remain airborne while the helicopter slowly yawed to the right. The CFI instructed him not to let the helicopter contact the ground and he continued to apply up collective while the helicopter continued yawing to the right. As he was applying up collective he felt the CFI grasp the cyclic and collective controls and heard the rotor rpm and engine noise increase. He later stated that while it is not clear to him which of them applied power, he was fairly certain that he did not. The helicopter began a rapid right yaw possible landing briefly then becoming airborne while yawing 360 degrees and climbing to an estimated height of 10 to 20 feet above ground level. The CFI attempted to hover then announced he was rolling the throttle to idle. The helicopter then began a rapid descent, landed hard, and rolled towards the left side. He and the CFI initiated the emergency shutdown procedures and exited the helicopter. The CFI stated that he briefed the student on the emergency procedure to be performed (loss of tail rotor thrust) and also the proper response which would be to slowly reduce throttle and cushion the landing with collective control. The CFI initiated the maneuver by applying right anti-torque pedal input and the student responded by decreasing throttle. As the rotation stopped the helicopter settled and made contact with the ground with somemovement. The student was uncomfortable with the touchdown and applied throttle control. Though his (CFI’s) hands were on the flight controls he was not guarding the throttle closely enough to arrest the quick application of throttle. The helicopter became airborne and began yawing very quickly to the right which was not corrected by left anti-torque pedal input. He closed the throttle which stopped the right yaw but at that point the helicopter was 7 to 10 feet and rotor rpm was insufficient to maintain flight. He applied collective and forward cyclic to cushion the landing but the helicopter landed hard causing the left skid gear to collapse. The National Transportation Safety Board (NTSB) Pilot/Operator Aircraft Accident/Incident Report submitted by the operator indicated there was no mechanical failure or malfunction. Following the accident the engine was removed from the helicopter, sent to the manufacturer’s facility to be functionally tested. With Federal Aviation Administration oversight the engine was ran and found to operate normally. The emergency procedures for loss of tail rotor thrust while in a hover, specified in the flight manual, indicate to place the twistgrip in the ground idle position and to perform a hovering autorotation. ## Aircraft - Registration: [N502SL](https://openairdocs.org/aircraft/N502SL), registered now, S/N 0244E (OpenAirDocs) - Reported make and model: MCDONNELL DOUGLAS HELICOPTER 369E - Registry model: [Mcdonnell Douglas Helicopter 369E](https://openairdocs.org/model/mcdonnell-douglas-helicopter-369e) (registry code 3027369) (OpenAirDocs) - Category: Helicopter - Serial number: 0244E - Airframe hours: 4961 - Engines: Allison 250-C20B 420 hp turbo shaft - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Sc Law Enforcement Division - Registered owner: Sc Law Enforcement Division - Airworthiness certificate: Standard, Normal - Last inspection: Annual, September 10, 2009 - Departed: 2SC6, Columbia, SC - Destination: FDW, Winnsboro, SC - Airport: FDW, Fairfield County Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 35; injuries: none; commercial, private; airplane ratings: single-engine land; instrument ratings: helicopter; medical: class 2, without waivers/limitations; seat: right; flight hours: 2,150 total, 600 in this make and model, 2,050 as pilot in command, 80 in the last 90 days, 30 in the last 30 days - Student pilot; age 47; injuries: none; commercial; medical: class 2, without waivers/limitations; last flight review February 25, 2009; seat: left; flight hours: 1,766 total, 362 in this make and model, 859 as pilot in command, 53 in the last 90 days, 22 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 320° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 61 °F, dew point 30 °F - Altimeter: 30.28 inHg - Observed at: FDW ## 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 20091019025969A](https://openairdocs.org/incident/20091019025969A), Oct 19, 2009: Mcdonnell D 369E, Fairfield, SC, Substantial damage. On October 19, 2009, at 1515HRS, in VMC conditions, a law enforcement helicopter was conducting recurrent training of pilots using a contract flight… ## Docket (7 files) The files NTSB released with the investigation on March 9, 2010, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=74931. 26.8 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 929 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40325185&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - FAA Inspector Statement (item 2, .PDF, 38 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40325186&FileExtension=.PDF&FileName=FAA%20Inspector%20Statement-Redacted.PDF - Excerpts of Report from Rolls-Royce (item 3, .PDF, 22.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40325187&FileExtension=.PDF&FileName=Excerpts%20of%20Report%20from%20Rolls-Royce-Redacted.PDF - Excerpts from Flight Manual (item 4, .PDF, 2.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40325188&FileExtension=.PDF&FileName=Excerpts%20from%20Flight%20Manual-Master.PDF - Statements from Flight Crew (item 5, .PDF, 362 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40325189&FileExtension=.PDF&FileName=Statements%20from%20Flight%20Crew-Redacted.PDF - Statement of Party Representatives to NTSB Investigation (item 6, .PDF, 75 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40325190&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 7, .PDF, 81 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40325191&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.