# NTSB SEA98LA017: Bell TH-1L, N8160G, Canby, OR, November 25, 1997 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: November 25, 1997, 10:30 local (18:30 UTC) - Place: Canby, OR - Coordinates: 45.210453, -122.659919 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.2105&lon=-122.6599&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 7 minor - Status: Completed, report December 1, 1999 - Report: Approved by Office Director - NTSB case key (mKey): 42739 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA98LA017 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42739/pdf - Page: https://openairdocs.org/ntsb/SEA98LA017 ## Probable cause The pilot's allowance of excessive airspeed resulting in the long-line hook impacting the tail rotor, and his allowance of an airspeed bleed-off preventing a successful run-on landing due to a loss of yaw control. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, cruise - external load cable/hook - blade strike (cause) - airspeed - excessive, pilot in command (cause) - Forced landing, descent - emergency - Hard landing, emergency landing - run on landing - attempted - airspeed - inadequate, pilot in command (cause) ## Analysis The pilot was repositioning the helicopter to a new work location with the 30 foot long-line in trail. While en route at 80 knots and 500 feet AGL, the pilot lost view of the line and hook in the aircraft's chin mirror when, in his words it 'became unstable.' Shortly thereafter, the hook impacted the tail-rotor blade assembly. The pilot then attempted to execute a run-on landing, but allowed his airspeed to bleed off beyond the point where he could maintain any directional control. The aircraft then began a right yaw and, after approximately 720 degrees of revolution, impacted the ground in a near level attitude with a near vertical flight path. ## Factual narrative On November 25, 1997, approximately 1030 Pacific standard time, a Bell TH-1L rotorcraft, N8160G, registered to Kenneth G. Guthrie, d/b/a Blue Bird Helicopters, and being flown by a commercial pilot, was substantially damaged during an emergency landing in a field following a loss of control while in cruise approximately five nautical miles south of Canby, Oregon. The pilot and six passengers sustained minor injuries. Visual meteorological conditions existed and no flight plan had been filed. The flight, which had been engaged in external long-line operations (slinging Christmas trees), was repositioning with the six member ground crew team. The flight was to have been operated under 14CFR133, and originated from a site near Molalla, Oregon, approximately 1025. The pilot reported that he was repositioning the helicopter to another work site with the 30 foot long-line trailing from the aircraft, and that "the hook (was) trailing smoothly beneath the aircraft as observed by myself in the chin mirror" and that "the hook suddenly became unstable and could no longer be seen in the chin mirror." Shortly thereafter the pilot heard a loud "bang" and felt the aircraft "lurch." The pilot, having been operating the helicopter at 80 knots and approximately 500 feet above ground at the time of the event, attempted to execute a run-on landing to a nearby field. He reported that "as I attempted to roll out on final I realized that I had allowed my airspeed to bleed off beyond the point where I could maintain any directional control with cyclic." The aircraft then began to yaw right, and after approximately 720 degrees of revolution impacted the ground in a near level attitude with a near vertical flight path. An FAA inspector responding to the accident site reported finding fragments of aluminum rotor blade imbedded in the hook at the end of the long-line. ## Aircraft - Registration: [N8160G](https://openairdocs.org/deregistered/N8160G-2017-03-21), registration cancelled 2017-03-21, S/N 157839 (OpenAirDocs) - Reported make and model: Bell TH-1L - Registry model: [Bell TH-1L](https://openairdocs.org/model/bell-th-1l) (registry code 1180817) (OpenAirDocs) - Registry engine: [Lycoming T-53 series](https://openairdocs.org/engine/lycoming-t-53-series) (registry code 41549, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 157839 - Engines: Lycoming T53-L-13B 1400 horsepower turbo shaft - Damage: Substantial damage - Flight: Other work use, Part 133 - Registered owner: Guthrie, Kenneth, G. - Airworthiness certificate: Special, Restricted (Special) - Departed: MOLALLA, OR - Destination: OR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 53; commercial; instrument ratings: helicopter; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 11,329 total, 52 in this make and model, 7,439 as pilot in command, 86 in the last 90 days, 53 in the last 30 days, 7 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 30° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 52 °F, dew point 45 °F - Altimeter: 30.00 inHg - Observed at: AUO, 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 19971125034969A](https://openairdocs.org/incident/19971125034969A), Nov 25, 1997: Bell TH1L, Canby, OR, Substantial damage. Bell TH-1L acft crashed und unk circ. Canby, OR. (.19)on November 25, 1997, approxiamtely 1120 pacific standard time, a Bell TH-1L rotorcraft, N8160G,… 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.