# NTSB ANC99TA090: Bell 206B, N47122, Deadhorse, AK, July 8, 1999 - Type: NTSB accident investigation - Classification: Accident · No injuries · Final report - Date: July 8, 1999, 12:30 local (20:30 UTC) - Place: Deadhorse, AK - Coordinates: 70.429885, -149.289657 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=70.4299&lon=-149.2897&mi=10 - Phase of flight: [Standing](https://openairdocs.org/ntsb-phases/150) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 4 uninjured - Status: Completed, report November 30, 2000 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 46774 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC99TA090 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/46774/pdf - Page: https://openairdocs.org/ntsb/ANC99TA090 ## Probable cause A failure of the pilot-in-command to perform an adequate preflight inspection, and remove a rotor blade tie-down strap. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Miscellaneous/other, standing - starting engine(s) - starting procedure - initiated, pilot in command - vertical stabilizer - bent - rotor blade tie-down(s) - not removed, pilot in command (cause) - misc rotorcraft,tail boom - twisted - aircraft preflight - inadequate, pilot in command (cause) ## Analysis The pilot for an on-demand helicopter company was beginning a flight that was being operated as a visual flight rules (VFR) U.S. Government flight by the U.S Department of Interior, Bureau of Land Management. The pilot loaded his passengers into the helicopter at a remote biological survey site. He then began an engine start, but a main rotor blade tie-down strap was still attached to one of the rotor blades. As the rotor blades began to turn, the strap struck the upper end of the vertical stabilizer, crushing the leading edge in an aft direction. The helicopter's tail boom was deformed and wrinkled, just forward of the tail rotor gear box. ## Factual narrative On July 8, 1999, about 1230 Alaska daylight time, a Bell 206B helicopter, N47122, sustained substantial damage during engine start-up, about 75 miles southwest of Deadhorse, Alaska. The helicopter was being operated as a visual flight rules (VFR) U.S. Government flight by the U.S Department of Interior, Bureau of Land Management, Fairbanks, Alaska, when the accident occurred. The helicopter, provided by Tundra Copters Inc., Fairbanks, Alaska, was utilized on an on-demand 14 CFR Part 135 flight. The certificated commercial pilot, and the three passengers, were not injured. Visual meteorological conditions prevailed. VFR company flight following procedures were in effect. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on July 8, 1999, the director of operations for Tundra Copters Inc., reported the pilot loaded his passengers into the helicopter at a remote biological survey site. The pilot then began an engine start, but a main rotor blade tie-down strap was still attached to one of the rotor blades. As the rotor blades began to turn, the strap struck the upper end of the vertical stabilizer, crushing the leading edge in an aft direction. The helicopter's tail boom was deformed and wrinkled, just forward of the tail rotor gear box. ## Aircraft - Registration: [N47122](https://openairdocs.org/deregistered/N47122-2002-11-15), registration cancelled 2002-11-15, S/N 971, built 1973 (OpenAirDocs) - Reported make and model: Bell 206B - Registry model: [Bell 206B](https://openairdocs.org/model/bell-206b) (registry code 1181511) (OpenAirDocs) - Registry engine: [Allison 250 SER 400HP](https://openairdocs.org/engine/allison-250-ser-400hp) (registry code 03013, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 971 - Airframe hours: 6274 - Engines: Allison C20B 420 horsepower turbo shaft - Damage: Substantial damage - Flight: Part 135 - Operator: U.S. Bureau Of Land Management - Registered owner: Tundra Copters Inc. - Airworthiness certificate: Standard, Normal - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 51; flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: right; flight hours: 6,500 total, 1,100 in this make and model, 6,000 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 40° at 3 knots - Visibility: 20 statute miles - Lowest ceiling: none - Temperature: 70 °F - Altimeter: 29.00 inHg ## 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 19990708008519A](https://openairdocs.org/incident/19990708008519A), Jul 8, 1999: Bell 206B, Deadhorse, AK, Substantial damage. Tundra copters air taxi (1973 Bell 206B helicopter) crashed on take-off and sustained substantial damage, no injuries were reported to the pilot and 4 pax,… 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.