# NTSB ERA21LA357: Enstrom F28, N51789, Toughkenamon, PA, September 8, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: September 8, 2021, 16:45 local (20:45 UTC) - Place: Toughkenamon, PA - Coordinates: 39.830512, -75.769754 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.8305&lon=-75.7698&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-hover: Loss of tail rotor effectiveness](https://openairdocs.org/ntsb-events/242) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Eastern Region Aviation - Parties: FAA FSDO - NTSB case key (mKey): 103863 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA21LA357 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103863/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103863 - Page: https://openairdocs.org/ntsb/ERA21LA357 ## Probable cause The pilot’s failure to maintain control of the helicopter during an out-of-ground effect hover in a gusty wind, due to 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: [Enstrom F-28C, 5 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=3300407), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Tail rotor](https://openairdocs.org/ntsb-findings/01046400): Aircraft › Aircraft propeller/rotor · Capability exceeded (probable cause); cases with it: [Enstrom F-28C, 1 case](https://openairdocs.org/ntsb-findings/01046400/cases.md?model=3300407), [All aircraft, 23 cases](https://openairdocs.org/ntsb-findings/01046400/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-hover: Loss of tail rotor effectiveness](https://openairdocs.org/ntsb-events/242) (defining event); cases with it: [Enstrom F-28C, 1 case](https://openairdocs.org/ntsb-events/242/sequence.md?model=3300407), [All aircraft, 100 cases](https://openairdocs.org/ntsb-events/242/sequence.md) - [Maneuvering-hover: Loss of control in flight](https://openairdocs.org/ntsb-events/240); cases with it: [Enstrom F-28C, 4 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=3300407), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Enstrom F-28C, 3 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=3300407), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot performed a straight in approach to runway 24 and then entered an out-of-ground-effect hover at 30 to 40 ft above ground level. He made a right turn to hover taxi to the fueling area. At that time, he noticed that the rotor rpm was low, and he attempted to increase it; however, the helicopter spun right, descended and impacted a grass area near a taxiway. The recorded wind at the airport about the time of the accident was variable at 4 knots, gusting to 10 knots. The pilot reported 10 to 12 knot gusts from the east at the time of the accident and previous and subsequent weather recordings indicated wind gusts from the south. Examination of the wreckage by a Federal Aviation Administration inspector revealed substantial damage to the lower right fuselage. The examination did not reveal any preimpact mechanical malfunctions, nor did the pilot report any. It is likely that the helicopter was in an out-of-ground effect hover with a direct or quartering tailwind, which resulted in a loss of tail rotor effectiveness. ## Aircraft - Registration: [N51789](https://openairdocs.org/aircraft/N51789), registered now, S/N 454-2, built 1978 (OpenAirDocs) - Reported make and model: ENSTROM F28 (C) - Registry model: [Enstrom F-28C](https://openairdocs.org/model/enstrom-f-28c) (registry code 3300407) (OpenAirDocs) - Registry engine: [Lycoming HIO-360 series](https://openairdocs.org/engine/lycoming-hio-360-series) (registry code 41524, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 454-2 - Year built: 1978 - Airframe hours: 3802 - Engines: Lycoming HIO-360 190 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 21, 2021 - Airport: N57, New Garden Airport, runway 24, 3,693 × 60 ft, asphalt - Equipment: Handheld GPS, ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 75; injuries: none; private; airplane ratings: single-engine land; medical: basicmed; last flight review April 25, 2020; seat: left; restraint: lap only; flight hours: 525 total, 348 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 4 knots, gusting 10 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 70 °F - Altimeter: 2979.00 inHg - Observed at: MQS, 10 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 20210908015469A](https://openairdocs.org/incident/20210908015469A), Sep 8, 2021: Enstrom F-28C, Toughkenamon, PA, Substantial damage. Pilot was hovering helicopter in a left to right crosswind. The pilot stated that he did not obtain a weather brief that day. He experienced tail rotor vortex… ## Other investigations on N51789 (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 CHI80FEG19](https://openairdocs.org/ntsb/CHI80FEG19), Jul 13, 1980: Enstrom F-28 (N51789), Xenia, OH, substantial damage ## Docket (4 files) The files NTSB released with the investigation on April 28, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103863. 2.1 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 7 pages, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12775657&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf - Interview summaries (item 2, PDF, 3 pages, 134 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12774390&FileExtension=pdf&FileName=Interview%20Summaries-Rel.pdf - Weather report (item 3, PDF, 1 page, 46 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12775554&FileExtension=pdf&FileName=Metars-Rel.pdf - Photo array (item 4, PDF, 1 page, 465 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12775143&FileExtension=pdf&FileName=Photo%20Array-Rel.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.