# NTSB SEA94LA149: Hiller-Soloy UH-12L4, N67264, Clarkston, WA, June 14, 1994 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: June 14, 1994, 16:50 local (23:50 UTC) - Place: Clarkston, WA - Coordinates: 46.360702, -117.219871 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=46.3607&lon=-117.2199&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 3 minor - Status: Completed, report December 7, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 41952 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA94LA149 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41952/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=41952 - Page: https://openairdocs.org/ntsb/SEA94LA149 ## Probable cause DISCONNECTION OF THE BALLAST BAR AFT RETAINING PIN. FACTOR(S) WERE: TAIL ROTOR BLADE SEPARATION AND REDUCED AIRCRAFT CONTROL. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, cruise - safety system(other) - disconnected (cause) - Loss of control - in flight, cruise - rotor system,tail rotor blade - separation (contributing factor) - Forced landing, descent - emergency - Hard landing, landing - flare/touchdown - aircraft control - reduced (contributing factor) ## Analysis WHILE IN FLIGHT THE BALLAST BAR AFT RETAINING PIN DISCONNECTED ALLOWING THE BALLAST BAR TO DISENGAGE FROM THE AFT BOLT AND SWING INTO THE PLANE OF ROTATION OF THE TAIL ROTOR BLADES. BOTH TAIL ROTOR BLADES SEPARATED AND A LOSS OF DIRECTIONAL CONTROL FOLLOWED. THE PILOT, UNABLE TO MAINTAIN FULL CONTROL OF THE ROTORCRAFT, EXECUTED AN AUTOROTATION TO A HARD LANDING. ## Factual narrative On June 14, 1994, approximately 1650 hours Pacific daylight time (pdt), a Hiller/Soloy UH-12L4, N67264, registered to and being flown by James R. Pope, a certificated commercial pilot, was substantially damaged during an autorotation landing to a hillside following a loss of directional control while in cruise approximately 5 miles southwest of Clarkston, Washington. The pilot and two passengers received minor injuries. Visual meteorological conditions existed at the time, and no flight plan had been filed. The flight, which was a post maintenance evaluation, was to have been operated in accordance with 14CFR91, and originated from the pilot's private helicopter base near Clarkston, Washington, approximately 1600. The pilot reported to the Investigator in Charge that while in slow cruise several hundred feet above ground he heard a "bang" and began to lose directional control of the rotorcraft. He attempted to regain directional control by lowering the nose and increasing airspeed. This, however, was unsuccessful and the rotorcraft entered a spiral. He then elected to execute a powered autorotation to a forced landing. The pilot reported that during the flare to sloped terrain the aircraft landed hard and the main rotor blades and tail boom impacted the ground and separated (refer to photograph 01). On site examination by FAA Inspector Tex Gaston revealed that a substantial portion of both tail rotor blades had separated (refer to photograph 02). Further examination revealed that the aft retaining pin which inserts through the side (lateral axis) of the movable, ballast weight bar, was absent. Its retaining wire, which attaches the pin to the tailboom, was observed to be broken. The 17 pound ballast bar, which is used to change the center of gravity of the rotorcraft dependent upon the inclusion of passengers, was then able to drop down vertically a short distance and release from the aft retaining bolt. The ballast bar then, still retained by the forward bolt, could now swing left/ right allowing its aft end to enter the plane of rotation of the tail rotor blade. Scratch marks were observed on the aft end of the ballast bar (refer to photograph 03). The pilot reported to Inspector Gaston that the aft pin had been installed prior to departing on the flight. ## Aircraft - Registration: [N67264](https://openairdocs.org/deregistered/N67264-2012-02-24), registration cancelled 2012-02-24, S/N 2509, built 1965 (OpenAirDocs) - Reported make and model: Hiller-Soloy UH-12L4 - Registry model: [Hiller UH-12E](https://openairdocs.org/model/hiller-uh-12e) (registry code 4360122) (OpenAirDocs) - Registry engine: [Allison 250 series](https://openairdocs.org/engine/allison-250-series) (registry code 03014, turbo-prop) (OpenAirDocs) - Category: Helicopter - Serial number: 2509 - Airframe hours: 3846 - Engines: ALLISON 250-C20B 420 horsepower turbo shaft - Damage: Substantial damage - Flight: Part 91 - Operator: Pope, James R. - Registered owner: Pope, James, R. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 13, 1994, 0 hours before - Departed: ASOTIN, WA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 58; commercial; airplane ratings: single-engine land; instrument ratings: helicopter, airplane; medical: class 2, valid medical--w/ waivers/lim; seat: front; flight hours: 26,000 total, 8,000 in this make and model, 26,000 as pilot in command, 450 in the last 90 days, 200 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 100° at 12 knots - Visibility: 30 statute miles - Lowest ceiling: 9,000 ft broken - Temperature: 61 °F, dew point 36 °F - Altimeter: 29.00 inHg - Observed at: LWS, 5 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 19940614021009A](https://openairdocs.org/incident/19940614021009A), Jun 14, 1994: Hiller UH12L4, Clarkston, WA, Substantial damage. Lost altitude and rotor control. Auto rotated. Hard impact. Chopped tails. Ballast weight pin lost. Bar hit rotor. ## Other investigations on N67264 (2) 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. - [NTSB WPR10FA440](https://openairdocs.org/ntsb/WPR10FA440), Aug 31, 2010: Hiller UH 12E (N67264), Kamiah, ID, substantial damage, 3 fatal. Probable cause: In-flight impact of a passenger's metal clipboard with the helicopter’s tail rotor, which resulted in destruction of the tail rotor and subsequent loss of control of the helicopter. The original… - [NTSB SEA99LA031](https://openairdocs.org/ntsb/SEA99LA031), Jan 19, 1999: Hiller UH-12E (N67264), Tensed, ID, substantial damage. Probable cause: The pilot-in-command's inadequate fuel management which resulted in fuel exhaustion. Contributing factors were the absence of cautionary markings on the fuel gauge, and high trees at the accident… ## Docket (7 files) The files NTSB released with the investigation on June 6, 1995, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=41952. 2.4 MB in all. - Supplement S (item 1, .PDF, 44 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40019717&FileExtension=.PDF&FileName=Supplement%20S-Master.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1/2 (item 2, .PDF, 1.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40376735&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%2F2-Redacted.PDF - Maps or Charts of Accident Area, Wreckage Diagrams (item 3, .PDF, 232 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40019719&FileExtension=.PDF&FileName=Maps%20or%20Charts%20of%20Accident%20Area,%20Wreckage%20Diagrams-Master.PDF - FAA Inspector's Statement (item 4, .PDF, 52 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40376736&FileExtension=.PDF&FileName=FAA%20Inspector%27s%20Statement-Redacted.PDF - Photo 1. A view of the rotorcraft at the ground impact site. Photograph provided by FAA. No negative. (item 5, .PDF, 54 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40019721&FileExtension=.PDF&FileName=Photo%201.%20%20A%20view%20of%20the%20rotorcraft%20at%20the%20ground%20impact%20site.%20%20Photograph%20provided%20by%20FAA.%20%20No%20negative.-Master.PDF - Photo 2. A view of the aft tailboom showing the ballast weight and tail rotor system. Note the separated outboard rotor blades. Photograph provided by FAA. No negative. (item 6, .PDF, 78 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40019722&FileExtension=.PDF&FileName=Photo%202.%20%20A%20view%20of%20the%20aft%20tailboom%20showing%20the%20ballast%20weight%20and%20tail%20rotor%20system.%20%20Note%20the%20separated%20outboard%20rotor%20blades.%20%20Photograph%20provided%20by%20FAA.%20%20No%20negative.-Master.PDF - Photo3.View of ballast weight.Forward retaining pin still engaged through ballast weight&retaining bolt(1),missing pin at aft end of the weight allowing weight to drop down&release from the aft bolt(2),scratch marks on unders (item 7, .PDF, 56 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40019723&FileExtension=.PDF&FileName=Photo3.View%20of%20ballast%20weight.Forward%20retaining%20pin%20still%20engaged%20through%20ballast%20weight%26retaining%20bolt(1),missing%20pin%20at%20aft%20end%20of%20the%20weight%20allowing%20weight%20to%20drop%20down%26release%20from%20the%20aft%20bolt(2),scratch%20marks%20on%20unders-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.