# NTSB ERA20LA310: Robinson R22, N194HC, Fort Myers, FL, September 6, 2020 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: September 6, 2020, 09:00 local (13:00 UTC) - Place: Fort Myers, FL - Coordinates: 26.586666, -81.863334 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=26.5867&lon=-81.8633&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Eastern Region Aviation - NTSB case key (mKey): 101940 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA20LA310 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/101940/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=101940 - Page: https://openairdocs.org/ntsb/ERA20LA310 ## Probable cause Foreign object damage of the turning tailrotor by a soft-bodied object, which resulted in the sudden stoppage of the tailrotor and the catastrophic failure of the tailrotor assembly and its mount structure. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Tail rotor drive system: tail rotor gearbox](https://openairdocs.org/ntsb-findings/01046520): Aircraft › Aircraft propeller/rotor · Damaged/degraded (probable cause); cases with it: [Robinson Helicopter R22 MARINER, 1 case](https://openairdocs.org/ntsb-findings/01046520/cases.md?model=7640115), [All aircraft, 12 cases](https://openairdocs.org/ntsb-findings/01046520/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) (defining event); cases with it: [Robinson Helicopter R22 MARINER, 1 case](https://openairdocs.org/ntsb-events/900/sequence.md?model=7640115), [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) ## Analysis The flight instructor and pilot receiving instruction had just started the helicopter when, as the engine accelerated to near its operating rpm, both pilots heard a loud “bang.” The pilot receiving instruction leaned out his door and announced that “the tail was hanging off the back of the aircraft.” The pilots shut down the helicopter and reported the event to the helicopter’s owner and his mechanic. Examination of the tailrotor driveshaft, tailrotor gearbox, tailrotor blades, and the tailcone section forward of the tailrotor gearbox all revealed signatures consistent with overstress fracture on the fracture surfaces. There was no evidence of fatigue or foreign object damage (FOD). The fractures and impact signatures were consistent with the fracture of the tailrotor gearbox mount structure (bulkhead) of the tailcone, followed by impact signatures of the rotating tailrotor assembly against the vertical and horizontal stabilizers. The impact signatures were consistent with a soft-bodied object (such as a plastic shopping bag or Mylar balloon) striking the turning tailrotor, which resulted in sudden-stoppage and overstress fractures of the tailrotor gearbox mount and the associated parts of the tailrotor assembly. ## Factual narrative On September 6, 2020, about 0900 eastern daylight time, a Robinson R22 Mariner helicopter, N194HC, was involved in an accident near Fort Myers, Florida. The commercial pilot and his airline transport-rated pilot receiving instruction were not injured. The helicopter was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The instructor and pilot receiving instruction each submitted written statements, and their versions of events were consistent throughout. The preflight and engine-start procedures were completed with no anomalies noted. As the engine accelerated to near its operating rpm, both pilots heard a loud “bang.” The pilot receiving instruction leaned out his door and announced that “the tail was hanging off the back of the aircraft.” The pilots shut down the helicopter and reported the event to the helicopter’s owner and his mechanic. In a telephone interview, the pilot receiving instruction said that, after the helicopter was shut down, he observed no evidence that an unsecured aircraft cover, clothing item, or bird had struck the tailrotor. He added that the only debris surrounding the helicopter on the ramp was aircraft wreckage. Examination of photographs revealed damage to the tailrotor driveshaft, tailrotor gearbox, tailrotor blades, and the tailcone’s section forward of the tailrotor gearbox. These areas and components were sectioned and forwarded to the NTSB Materials Laboratory in Washington, DC for examination. Examination of all the submitted components revealed signatures consistent with overstress fracture on all the fracture surfaces. There was no evidence of fatigue. There was no evidence (mechanical/paint transfer/biological) of foreign object damage (FOD). The fractures and impact signatures were consistent with the fracture of the tailrotor gearbox mount structure (bulkhead) of the tailcone, followed by impact signatures of the rotating tailrotor assembly against the vertical and horizontal stabilizers. ## Aircraft - Registration: [N194HC](https://openairdocs.org/aircraft/N194HC), registered now, S/N 1955M, built 1991 (OpenAirDocs) - Reported make and model: Robinson R22 (MARINER) - Registry model: [Robinson Helicopter R22 MARINER](https://openairdocs.org/model/robinson-helicopter-r22-mariner) (registry code 7640115) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 1955M - Year built: 1991 - Airframe hours: 6177.4 - Engines: Lycoming O-320 SERIES 160 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, August 11, 2020, 45 hours before - Departed: FMY, Fort Myers, FL - Destination: FMY, Fort Myers, FL - Airport: FMY, Page Field - Equipment: ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 54; injuries: none; commercial, private, flight instructor; airplane ratings: single-engine land, single-engine sea; instrument ratings: helicopter; medical: class 2, with waivers/limitations; seat: left; restraint: 3-point; flight hours: 2,200 total, 476 in this make and model, 1,861 as pilot in command, 243 in the last 90 days, 81 in the last 30 days, 7 in the last 24 hours - Student pilot; age 25; injuries: none; airline transport, flight instructor; airplane ratings: single-engine sea, single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review May 25, 2020; seat: right; restraint: 3-point; flight hours: 5,034 total, 8 in this make and model, 2,183 as pilot in command, 30 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 50° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 75 °F - Altimeter: 30.01 inHg - Observed at: FMY ## 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 20200906019539A](https://openairdocs.org/incident/20200906019539A), Sep 6, 2020: Robinson Helicopter Company R22 MARINER, Fort Myers, FL, Substantial damage. On 06-sept-2020, N194HC, a 1991 Robinson R22 mariner helicopter, s/n 1955M was involved in an accident at Page Field (fmy) Fort Myers, Florida. The two POB… ## Docket (7 files) The files NTSB released with the investigation on June 17, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=101940. 9.2 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12508571&FileExtension=pdf&FileName=NTSB%20Form%206120_Redacted-Rel.pdf - Pilot-rated passenger statement (item 2, PDF, 2 pages, 14 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12509582&FileExtension=pdf&FileName=Copilot%20Statement_Redacted-Rel.pdf - Copilot memorandum for record (item 3, PDF, 1 page, 117 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12510233&FileExtension=pdf&FileName=Memorandum%20for%20Record%20Felipe%20Santiago-Rel.pdf - Materials laboratory (item 4, PDF, 6 pages, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12509180&FileExtension=pdf&FileName=20-064%20Materials%20Lab%20Factual%20Report%20for%20ERA20LA310-Rel.pdf - NTSB memorandum - damage sequence (Robinson helicopter) (item 5, PDF, 5 pages, 2.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12509260&FileExtension=pdf&FileName=Memorandum%20for%20Thom%20Webster%20Robinson%20Helicopter-Rel.pdf - Photo array (item 6, PDF, 4 pages, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12509592&FileExtension=pdf&FileName=Photo%20Array-Rel.pdf - Release of aircraft wreckage, NTSB form 6120.15 (item 7, PDF, 3 pages, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12509058&FileExtension=pdf&FileName=Signed%20Wreckage%20Release_Redacted-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.