# NTSB WPR18LA226: Hughes 369, N105JL, Riverside, CA, August 17, 2018 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Class 3 · Limited · Final report - Date: August 17, 2018, 10:50 local (17:50 UTC) - Place: Riverside, CA - Coordinates: 33.930831, -117.4475 - Nearby events: https://openairdocs.org/map.md?lat=33.9308&lon=-117.4475&mi=10 - Phase of flight: [Emergency descent](https://openairdocs.org/ntsb-phases/600) (OpenAirDocs' grouping) - Defining event: [Autorotation: Hard landing](https://openairdocs.org/ntsb-events/092) - Highest injury: Serious injuries - Injuries: 1 serious, 1 minor - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: McDonnell Douglas Helicopters, Federal Aviation Administration, Western Helicopters Inc. - NTSB case key (mKey): 98093 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR18LA226 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/98093/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=98093 - Page: https://openairdocs.org/ntsb/WPR18LA226 ## Probable cause The instructor’s delayed remedial action to an excessive descent rate during a simulated autorotation, which resulted in a hard landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: descent rate](https://openairdocs.org/ntsb-findings/01062037): Aircraft › Aircraft oper/perf/capability · Incorrect use/operation (probable cause); cases with it: [Hughes Helicopters HUGHES 369D, 5 cases](https://openairdocs.org/ntsb-findings/01062037/cases.md?model=4470706), [All aircraft, 242 cases](https://openairdocs.org/ntsb-findings/01062037/cases.md) - [Misc hardware: fasteners](https://openairdocs.org/ntsb-findings/01071430): Aircraft › Fluids/misc hardware · Not installed/available; cases with it: [Hughes Helicopters HUGHES 369D, 1 case](https://openairdocs.org/ntsb-findings/01071430/cases.md?model=4470706), [All aircraft, 58 cases](https://openairdocs.org/ntsb-findings/01071430/cases.md) - [Attention/monitoring: monitoring other person](https://openairdocs.org/ntsb-findings/02021535): Personnel issues › Psychological · Instructor/check pilot (probable cause); cases with it: [Hughes Helicopters HUGHES 369D, 1 case](https://openairdocs.org/ntsb-findings/02021535/cases.md?model=4470706), [All aircraft, 200 cases](https://openairdocs.org/ntsb-findings/02021535/cases.md) - [Fuselage: seat/cargo attach fitting](https://openairdocs.org/ntsb-findings/01035347): Aircraft › Aircraft structures · Incorrect service/maintenance; cases with it: [Hughes Helicopters HUGHES 369D, 1 case](https://openairdocs.org/ntsb-findings/01035347/cases.md?model=4470706), [All aircraft, 27 cases](https://openairdocs.org/ntsb-findings/01035347/cases.md) - [Action: delayed action](https://openairdocs.org/ntsb-findings/02041025): Personnel issues › Action/decision · Instructor/check pilot (probable cause); cases with it: [Hughes Helicopters HUGHES 369D, 1 case](https://openairdocs.org/ntsb-findings/02041025/cases.md?model=4470706), [All aircraft, 894 cases](https://openairdocs.org/ntsb-findings/02041025/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Autorotation: Hard landing](https://openairdocs.org/ntsb-events/092) (defining event); cases with it: [Hughes Helicopters HUGHES 369D, 9 cases](https://openairdocs.org/ntsb-events/092/sequence.md?model=4470706), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis The pilot receiving instruction was performing a full-touchdown, 180° autorotation when the instructor noted that the helicopter was going to be short of the intended landing zone and advanced the throttle to initiate a power recovery. The helicopter continued to descend and landed hard and rolled over, resulting in substantial damage. The instructor reported no mechanical malfunctions with the helicopter or engine that would have precluded normal operation. It is likely that the instructor’s delayed response to the helicopter’s excessive rate of descent resulted in the hard landing. After egressing the helicopter, the instructor noted that the pilot receiving instruction had been ejected from the helicopter during the accident sequence. Examination of the restraint systems revealed that the cotter pins for the hook-end fitting that attached to the airframe seat belt fittings had not been installed. The centrifugal force generated by the rotation of the helicopter during the accident sequence was likely sufficient for the hook-end fitting, void of the cotter pin, to separate from the seat belt fitting, which then resulted in the student being ejected from the helicopter. As a result of the accident, the manufacturer issued a mandatory service bulletin requiring the installation of cotter pins in the seat belt assemblies. ## Factual narrative On August 17, 2018, about 1050 Pacific daylight time, a Hughes 369D helicopter, N105JL, was substantially damaged when it was involved in an accident near Riverside, California. The flight instructor sustained a minor injury, while the pilot receiving instruction was seriously injured. The helicopter was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The pilot performed several power recovery autorotations, then the instructor demonstrated a full-touchdown 180° autorotation. The pilot subsequently performed several power recovery 180° autorotations before the instructor asked him to perform a full-touchdown 180° autorotation. The instructor stated that, as the pilot turned the helicopter toward the runway, he saw that they were going to be short of the intended landing zone and advanced the throttle to perform a power recovery. The instructor then realized that the descent rate was greater than he anticipated, and he instructed the pilot to level the helicopter’s skids. The instructor reported that he “felt the absorbers on the skids collapsing” as the helicopter touched down, then he felt a large bump then rapid rotation of the airframe. After shutting off the fuel, the instructor egressed and saw that the pilot receiving instruction had been ejected from the helicopter during the accident sequence. Examination of the seat belts revealed that no cotter pins were installed in the hooked end fittings of each seat belt. The manufacturer reported that cotter pins were not delivered with the seat belts, nor were there any instructions from the manufacturer that cotter pins were required to be installed. Following the accident, on November 20, 2019, MD Helicopters issued Mandatory Service Bulletin SB369D-227, entitled “INSTALL COTTER PINS IN THE SEAT-BELT INSTALLATION.” In part, the Service Bulletin was issued “…to prevent the hook-ends from disengagement from the attachment points.” The bulletin further noted that, “Failure to comply with this bulletin can cause a pilot, copilot, or passenger to fall out of the helicopter in flight or on the ground.” ## Aircraft - Registration: [N105JL](https://openairdocs.org/deregistered/N105JL-2020-11-06), registration cancelled 2020-11-06, S/N 900807D, built 1980 (OpenAirDocs) - Reported make and model: Hughes 369 (D) - Registry model: [Hughes Helicopters HUGHES 369D](https://openairdocs.org/model/hughes-helicopters-hughes-369d) (registry code 4470706) (OpenAirDocs) - Registry engine: [Allison 250-C20 series](https://openairdocs.org/engine/allison-250-c20-series) (registry code 03020, turbo-prop) (OpenAirDocs) - Category: Helicopter - Serial number: 900807D - Year built: 1980 - Airframe hours: 11717.7 - Engines: Allison 250-C20B 450 horsepower turbo shaft - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Western Helicopters Inc - Registered owner: Helicopters Unlimited LLC - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, May 30, 2018, 60 hours before - Departed: RAL, Riverside, CA - Airport: RAL, Riverside Municiapal Airport, runway 34, 2,850 × 50 ft, concrete - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 62; injuries: minor; commercial; medical: class 2, with waivers/limitations; last flight review December 15, 2017; seat: right; restraint: 4-point; flight hours: 13,850 total, 13,000 in this make and model, 13,600 as pilot in command, 45 in the last 90 days, 27 in the last 30 days, 2 in the last 24 hours - Pilot; age 64; injuries: serious; private; medical: class 3, with waivers/limitations; seat: left; restraint: 4-point; flight hours: 2,500 total, 500 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 82 °F, dew point 67 °F - Altimeter: 30.06 inHg - Observed at: RAL, 1 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 20180817014409A](https://openairdocs.org/incident/20180817014409A), Aug 17, 2018: Hughes 369D, Riverside, CA, Substantial damage. N105JL, a Hughes HU-369D helicopter with two pilots onboard (a CFI and rated private pilot helicopter) were conducting autorotation training. While practicing… ## Docket (7 files) The files NTSB released with the investigation on June 17, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=98093. 9.2 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12182559&FileExtension=pdf&FileName=Pilot-Operator%20accident%20report%20form_Redacted-Rel.pdf - Meteorology (item 2, PDF, 1 page, 121 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12182642&FileExtension=pdf&FileName=Meteorological%20data-Rel.pdf - Summary of aircraft examination (item 3, PDF, 5 pages, 260 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12182696&FileExtension=pdf&FileName=Summary%20of%20Aircraft%20Examination-Rel.pdf - MD helicopters service bulletin 369D-227 (item 4, PDF, 6 pages, 109 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12181827&FileExtension=pdf&FileName=MD%20Helicopter%20Service%20Bulletin%20369D-227-Rel.pdf - Statement of party representatives to NTSB investigation (item 5, PDF, 2 pages, 5.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12182141&FileExtension=pdf&FileName=Party%20forms_Redacted-Rel.pdf - Release of aircraft wreckage, NTSB form 6120.15 (item 6, PDF, 1 page, 202 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12183030&FileExtension=pdf&FileName=NTSB%20Release%20of%20Wreakage%20form_Redacted-Rel.pdf - Photo array of helicopter damage (item 7, PDF, 4 pages, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12182779&FileExtension=pdf&FileName=Photo%20array%20of%20damage%20to%20helicopter-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.