# NTSB WPR12LA341: Fairchild Hiller FH-1100, N5038F, Cody, WY, July 31, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 31, 2012, 09:20 local (15:20 UTC) - Place: Cody, WY - Coordinates: 44.417221, -109.138053 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.4172&lon=-109.1381&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333) - Highest injury: No injuries - Injuries: 4 uninjured - Status: Completed, report April 10, 2014 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: FAA FSDO - NTSB case key (mKey): 84562 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR12LA341 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/84562/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=84562 - Page: https://openairdocs.org/ntsb/WPR12LA341 ## Probable cause The failure of a tail rotor driveshaft coupling due to fatigue. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Flight control system](https://openairdocs.org/ntsb-findings/01022700): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Fairchild Hiller FH-1100, 1 case](https://openairdocs.org/ntsb-findings/01022700/cases.md?model=3376502), [All aircraft, 65 cases](https://openairdocs.org/ntsb-findings/01022700/cases.md) - [Flight control system](https://openairdocs.org/ntsb-findings/01022700): Aircraft › Aircraft systems · Fatigue/wear/corrosion (probable cause); cases with it: [Fairchild Hiller FH-1100, 1 case](https://openairdocs.org/ntsb-findings/01022700/cases.md?model=3376502), [All aircraft, 65 cases](https://openairdocs.org/ntsb-findings/01022700/cases.md) - [Performance/control parameters: yaw control](https://openairdocs.org/ntsb-findings/01062024): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible; cases with it: [Fairchild Hiller FH-1100, 1 case](https://openairdocs.org/ntsb-findings/01062024/cases.md?model=3376502), [All aircraft, 149 cases](https://openairdocs.org/ntsb-findings/01062024/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Flight control sys malf/fail](https://openairdocs.org/ntsb-events/333) (defining event); cases with it: [Fairchild Hiller FH-1100, 2 cases](https://openairdocs.org/ntsb-events/333/sequence.md?model=3376502), [All aircraft, 410 cases](https://openairdocs.org/ntsb-events/333/sequence.md) - [Autorotation: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [Fairchild Hiller FH-1100, 1 case](https://openairdocs.org/ntsb-events/092/sequence.md?model=3376502), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis The pilot reported that while in cruise flight, the rear of the helicopter suddenly began to vibrate. He performed an autorotation to a field, and the helicopter landed hard. The tailboom and main transmission mounts were substantially damaged. The pilot reported that a tail rotor driveshaft coupling had split in half, which resulted in a loss of tail rotor drive. Postaccident examination of the tail rotor driveshaft coupling revealed that the coupling failure was initiated by fatigue cracking. A complete history of the part was not available; therefore, the total time in service of the part could not be determined. ## Factual narrative On July 31, 2012, about 0920 mountain daylight time, a Fairchild Hiller FH-1100 helicopter, N5038F, was substantially damaged following the failure of its tail rotor drive shaft and subsequent autorotation to a hard landing near Cody, Wyoming. The commercial pilot and his three passengers were not injured. The helicopter was being operated by the pilot, doing business as Eclipse Helicopter Services, Cody, under the provisions of 14 Code of Federal Regulations Part 91. No flight plan had been filed for the local personal flight, which had originated about 1 hour before the accident. Visual meteorological conditions prevailed at the time of the accident. The pilot reported that while in cruise flight, there was a sudden onset of a vibration coming from the rear of the helicopter. He performed an autorotation to a field straight ahead. During the landing sequence, the helicopter spun to the right 180 degrees. The landing skids, tail boom, and main transmission mounts were bent. The pilot reported that a tail rotor driveshaft coupling, identified as a Bendix 19E101-1D coupling, had split in half, which resulted in a loss of tail rotor drive. Postaccident examination of the tail rotor driveshaft coupling by the National Transportation Safety Board's Materials Laboratory in Washington, D.C., revealed that it failed due to fatigue cracking. A complete history of the part was not available; therefore, the total time in service of the part could not be determined. ## Aircraft - Registration: [N5038F](https://openairdocs.org/deregistered/N5038F-2018-03-14), registration cancelled 2018-03-14, S/N 186, built 1969 (OpenAirDocs) - Reported make and model: FAIRCHILD HILLER FH-1100 - Registry model: [Fairchild Hiller FH-1100](https://openairdocs.org/model/fairchild-hiller-fh-1100) (registry code 3376502) (OpenAirDocs) - Registry engine: [Allison 250 SER 250HP](https://openairdocs.org/engine/allison-250-ser-250hp) (registry code 03002, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 186 - Year built: 1969 - Airframe hours: 2250 - Engines: Allison 250-C18 317 horsepower turbo shaft - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Harrison Timothy Bruce, doing business as Eclipse Helicopter Services - Registered owner: Harrison Timothy Bruce - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 2, 2012 - Departed: Cody, WY - Destination: Cody, WY - Flight plan: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 56; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review December 3, 2011; seat: right; restraint: lap only; flight hours: 893 total, 77 in this make and model, 14 in the last 90 days, 14 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 40° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 75 °F, dew point 45 °F - Altimeter: 30.13 inHg - Observed at: COD, 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 20120731015749A](https://openairdocs.org/incident/20120731015749A), Jul 31, 2012: Fairchild Hiller FH-1100, Cody, WY, Substantial damage. On 07/31/2012 at approximately 1120 hrs MDT, N5038F, a Fairchild Hiller model FH-1100 rotorcraft sustained substantial damage upon impacting terrain seven… ## Docket (5 files) The files NTSB released with the investigation on March 20, 2014, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=84562. 7.8 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 649 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40406223&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Materials Laboratory 15 - Factual Report 13-061 (w 5 images) (item 2, .PDF, 994 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40397477&FileExtension=.PDF&FileName=Materials%20Laboratory%2015%20-%20Factual%20Report%2013-061%20(w%205%20images)-Master.PDF - Photo 1. Coupling (item 3, .PDF, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40406226&FileExtension=.PDF&FileName=Photo%201.%20%20Coupling-Master.PDF - Photo 2. Coupling (item 4, .PDF, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40406227&FileExtension=.PDF&FileName=Photo%202.%20%20Coupling-Master.PDF - Photo 3. Coupling (item 5, .PDF, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40406228&FileExtension=.PDF&FileName=Photo%203.%20Coupling-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.