# NTSB WPR20TA039: Enstrom F28, N65RS, Riverton, UT, December 11, 2019 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Final report - Date: December 11, 2019, 16:00 local (23:00 UTC) - Place: Riverton, UT - Coordinates: 40.483055, -111.940551 - Nearby events: https://openairdocs.org/map.md?lat=40.4831&lon=-111.9406&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: FAA - NTSB case key (mKey): 100683 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR20TA039 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/100683/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=100683 - Page: https://openairdocs.org/ntsb/WPR20TA039 ## Probable cause The noncertificated pilot’s decision to operate a deregistered helicopter, which resulted in a component failure and subsequent loss of control and hard landing. Contributing to the accident was the lack of recent maintenance on the helicopter. ## 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: [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Action: incorrect action selection](https://openairdocs.org/ntsb-findings/02041010): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [All aircraft, 397 cases](https://openairdocs.org/ntsb-findings/02041010/cases.md) - [Action: lack of action](https://openairdocs.org/ntsb-findings/02041030): Personnel issues › Action/decision · Maintenance personnel (probable cause); cases with it: [All aircraft, 792 cases](https://openairdocs.org/ntsb-findings/02041030/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333) (defining event); cases with it: [All aircraft, 410 cases](https://openairdocs.org/ntsb-events/333/sequence.md) - [Landing: Loss of control in flight](https://openairdocs.org/ntsb-events/240); cases with it: [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) - [Landing: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis The noncertificated pilot, who hadn’t flown “in years,” flew the helicopter to relocate it to another part of his property. The helicopter, which was not registered, and did not have an airworthiness certificate, had been stored outside and had not been maintained during the past 4 years. During the approach to land, the left-side tail rotor control cable was struck by the tail rotor, likely due to the prolonged lack of maintenance, which resulted in a loss of control. The pilot subsequently lowered the collective to land, and the main rotor blades struck a tree in the descent, and the helicopter landed hard. ## Factual narrative On December 11, 2019, about 1630 mountain standard time, an Enstrom F28F helicopter, N65RS, was substantially damaged when it was involved in an accident near Riverton, Utah. The pilot sustained minor injuries. The unregistered helicopter was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. In an interview with the pilot, he stated that he did not have a pilot’s certificate, that he had not flown the helicopter “in years” and intended to relocate it on his property. The pilot stated that on the approach to land, the tail rotor may have struck an object while he was about 6 feet above ground level (agl). The pilot initially increased the collective to go-around, but the main rotors struck a tree, so he then lowered the collective to land. The helicopter landed hard and sustained substantial damage to the fuselage, main rotor, and tail rotor assemblies. According to a witness, who was located across the street from the pilot’s residence, he observed the helicopter in the process of landing to an open field. He saw the helicopter get close to the ground, then it climbed up to about 30 or 40 feet above the ground and started to rotate about the main rotor. The helicopter then descended and struck a tree while falling to the ground. The helicopter came to rest on an area of the owner’s property. A tree near the wreckage exhibited broken branches, consistent with contact with the helicopter. Examination of the airframe revealed that the tail rotor gearbox housing was broken across the gear interface, consistent with a severe ground strike while the tail rotor was turning. The control cable on the left side was separated and the cable on the right side was intact. Both cables were unbolted from the tail rotor controls. The owner reported that he disconnected both cables to simplify recovering the wreckage. Both tail rotor blades were still attached to the hub, but they were damaged to the extent that the skins were separated from the spars. The bending was consistent with a severe ground strike while they were being driven. One of the blades had significant out-of-plane bending consistent with the aircraft rotating during the impact. The tail rotor control system from the cable attachments through the blades was intact and operated smoothly. The tail rotor cable on the left side of the aircraft was separated. The separation was located roughly in line with the tip of the tail rotor blade. Superficially, the separation was consistent with being cut by a blunt object with relatively high energy, such as a tail rotor blade. There were marks on the tail rotor drive shaft that appeared to match the tail rotor cable. These marks would be consistent with a section of tail rotor cable having contacted the drive shaft while it was rotating. Except for the separation of this cable and the fact that both cables had been disconnected at the tail rotor control yoke, the tail rotor control system was continuous. Except for the tail rotorcontrol cable, no other preaccident mechanical failures or malfunctions were found that would have precluded normal operation. The helicopter was manufactured in 1990. The last registration certificate on file with the FAA was for the prior owner, dated October 26, 1993. A document on file with the FAA cancelled the helicopter’s registration on September 6, 2012. The last airworthiness certificate on file with the FAA was dated February 21, 1990. The helicopter had been stored outdoors and not maintained in about four years. The last maintenance recorded for the aircraft and engine was September 18, 2015. One entry for the engine described a 100-hour inspection. At the beginning of the entry, it stated that the engine was inspected in accordance with a 100-hour inspection and found to be in an unairworthy condition. At the end of the same entry, it was signed with a statement that indicated the aircraft and/or components were inspected…and was found airworthy. One entry for the airframe described an annual inspection. At the beginning of the entry, it stated that the airframe had been inspected in accordance with an annual inspection and found to be unairworthy. A list of discrepancies has been supplied to the owner dated June 2, 2015. The owner did not provide a copy of the list. In the same entry it stated, “(82) Customer declined a main rotor blade track and balance check. Item is determined to be unairworthy by technicians due to excessive down time.” The pilot did not submit a National Transportation Safety Board Form 6120.1 Pilot/Operator Aircraft Accident/Incident Report. ## Aircraft - Registration: N65RS (not matched to a registry record) - Reported make and model: ENSTROM F28 - Category: Helicopter - Serial number: 766 - Year built: 1990 - Engines: Lycoming reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Dennis Goggin - Registered owner: Dennis Goggin - Airworthiness certificate: None - Last inspection: Annual, September 15, 2015 - Destination: Same as departure - Equipment: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Other flight crew; injuries: minor; flight hours: 250 total, 250 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 330° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: 6,500 ft overcast - Temperature: 34 °F, dew point 32 °F - Altimeter: 30.21 inHg - Observed at: KU42, 8 nm away - METAR: METAR KU42 112255Z AUTO 33004KT 10SM OVC065 01/00 A3021 RMK AO1 T00120000= ## 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 20191211021729A](https://openairdocs.org/incident/20191211021729A), Dec 11, 2019: Enstrom F-28F, Riverton, UT, Substantial damage. On December 11, 2019 at 1630 N65RS, serial number 766, Enstrom F28F operated by a non certificated pilot lost control of the aircraft, causing the aircraft to… ## Docket (9 files) The files NTSB released with the investigation on August 10, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=100683. 7.7 MB in all. - Pilot's statement (item 1, PDF, 2 pages, 116 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14039279&FileExtension=pdf&FileName=Pilot%20Statement-Rel.pdf - Witness statements (item 2, PDF, 1 page, 124 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14069111&FileExtension=pdf&FileName=Memo%20for%20Record%20WItness%20statement_Redacted-Rel.pdf - Airframe and engine examination report (item 3, PDF, 11 pages, 2.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14069912&FileExtension=pdf&FileName=Airframe%20and%20Engine%20Examination%20WPR20TA039-Rel.pdf - Logbook entries (item 4, PDF, 3 pages, 2.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14070094&FileExtension=pdf&FileName=Memo%20for%20Record%20Logbook%20entries_Redacted-Rel.pdf - Memo for record noncertificated pilot verification (item 5, PDF, 1 page, 130 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14070033&FileExtension=pdf&FileName=Memo%20for%20Record%20No%20pilots%20certificate-Rel.pdf - Helicopter registration and airworthiness documents (item 6, PDF, 6 pages, 871 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14235101&FileExtension=pdf&FileName=Memo%20for%20Record%20Deregistration%20of%20Helicopter_Redacted-Rel.pdf - Memo for record NTSB form 6120.1 (item 7, PDF, 1 page, 104 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14039164&FileExtension=pdf&FileName=Memo%20for%20Record%20Pilot%27s%20non-submission%20of%20NTSB%206120_1-Rel.pdf - Statement of party representatives to NTSB investigation (item 8, PDF, 1 page, 204 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14038488&FileExtension=pdf&FileName=Party%20Form%20Bluffdale%20Enstrom_Redacted-Rel.pdf - Photos (item 9, PDF, 2 pages, 944 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14286519&FileExtension=pdf&FileName=Photos%20WPR20TA039-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.