# NTSB ATL02LA130: Sikorsky S-55-QT, N2300Z, Orlando, FL, June 25, 2002 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: June 25, 2002, 12:45 local (16:45 UTC) - Place: Orlando, FL - Coordinates: 28.774999, -81.239997 - Nearby events: https://openairdocs.org/map.md?lat=28.7750&lon=-81.2400&mi=10 - Phase of flight: [Standing](https://openairdocs.org/ntsb-phases/150) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report August 26, 2003 - Report: Approved by Office Director - Parties: Orlando FSDO - NTSB case key (mKey): 55047 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL02LA130 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/55047/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=55047 - Page: https://openairdocs.org/ntsb/ATL02LA130 ## Probable cause Failure of the cyclic lateral control rod end bearing, and subsequent dynamic rollover. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, standing - idling rotors - rotorcraft flight control,control rod bearing - failure,total (contributing factor) - Roll over, standing - idling rotors ## Analysis During a maintenance check flight of the helicopter, two auto-rotations at max gross weight with a neutral center of gravity were conducted. During the second maintenance check flight, on the initial run-up the pilot engaged the rotor clutch and heard a loud "bang". The cyclic control pulled from the pilot's hand, and the pilot rolled the throttle to ground idle to regain control the cyclic control. The helicopter rocked from left to right and rolled over on its side. Examination of the airframe found that the cyclic lateral control rod end bearing on the transmission fractured. Examination of the fractured surfaces showed features typical of overstress. No other mechanical or flight control malfunction was reported by the pilot. ## Factual narrative On June 25, 2002, at 1245 eastern daylight time, a Sikorsky S-55-QT, N2300Z, registered to Foxtrot Incorporated and operated by a private pilot rolled over on the left side during a maintenance test flight at Sanford Airport, in Orlando, Florida. The maintenance test flight was operated under the provisions of Title 14 CFR Part 91 and visual flight rules. Visual meteorological conditions prevailed at the time of the accident. The helicopter sustained substantial damage, and the private pilot and passenger were not injured. The helicopter was on the second phase of the flight at the time of the accident on June 25, 2002. According to the pilot, during the maintenance check flight two auto-rotations at max gross weight with a neutral center of gravity were conducted. During the second maintenance check flight, on the initial run-up the pilot engaged the rotor clutch and heard a loud "bang". The cyclic control pulled from the pilot's hand, and the pilot rolled the throttle to ground idle to regain control the cyclic control. The helicopter rocked from left to right and rolled over on its side. Examination of the airframe found that the cyclic lateral control rod end bearing on the transmission fractured. There was no prior evidence of a preexisting fracture region or improper material. Scanning electron microscope examination of the fractured surfaces showed both fracture origin features typical of overstress. According to the operator of the helicopter, when the rotor is engaged the hydraulic boost is not effective until the main transmission reaches a speed where it produces sufficient hydraulic pressure to offset the back forces. These back forces are transmitted back to the cockpit flight controls, at this time the cyclic control pulled from the pilot's hand, and the control rod failed. Examination of the main rotor revealed all four main blades were curled from the blade tip to the main rotor. The fuselage displayed buckling in the tail cone section. The tail rotor was also curled inward. No other mechanical or flight control malfunctions were reported by the pilot. ## Aircraft - Registration: [N2300Z](https://openairdocs.org/aircraft/N2300Z), registered now, S/N 55750, built 1954 (OpenAirDocs) - Reported make and model: Sikorsky S-55-QT - Registry model: [Sikorsky S-55](https://openairdocs.org/model/sikorsky-s-55) (registry code 8141602) (OpenAirDocs) - Registry engine: [AiResearch TSE331 series](https://openairdocs.org/engine/airesearch-tse331-series) (registry code 01505, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 55-750 - Airframe hours: 6894 - Engines: National Flight Service 331-100A-511s 650 lbs thrust turbo shaft - Damage: Substantial damage - Flight: Flight test, Part 91 - Operator: Whisper Jet - Registered owner: Foxtrot Inc. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, October 11, 2001, 11 hours before - Departed: SFB, Sanford, FL - Destination: SFB, Sanford, FL - Airport: FA02, Sanford ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 64; injuries: none; private; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; last flight review July 1, 2001; seat: right; flight hours: 1,307 total, 128 in this make and model, 1,184 as pilot in command, 27 in the last 90 days, 11 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 160° at 10 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 73 °F - Altimeter: 30.13 inHg - Observed at: ORL, 7 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 20020625015499A](https://openairdocs.org/incident/20020625015499A), Jun 25, 2002: Skrsky S55, Orlando, FL, No damage. (-23) On the ground, while in the process of engaging the hydrometrical clutch at approximately 110 rotor RPM, there was a loud bang. The cyclic stick was… ## Docket (5 files) The files NTSB released with the investigation on June 6, 2003, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=55047. 8.2 MB in all. - Materials Laboratory 15 - Factual Report 02-116 (item 1, .PDF, 9 photos, 7.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40172676&FileExtension=.PDF&FileName=Materials%20Laboratory%2015%20-%20Factual%20Report%2002-116-Master.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 2, .PDF, 287 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448689&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Maintenance Report (item 3, .PDF, 198 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448690&FileExtension=.PDF&FileName=Maintenance%20Report-Master.PDF - Brearing Drawing (item 4, .PDF, 40 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40183225&FileExtension=.PDF&FileName=Brearing%20Drawing-Master.PDF - FAA Inspector's Statement (item 5, .PDF, 77 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448691&FileExtension=.PDF&FileName=FAA%20Inspector%27s%20Statement-Master.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.