# NTSB SEA01TA172: Bell 205, N458CC, Troy, MT, September 17, 2001 - Type: NTSB accident investigation - Classification: Accident · No injuries · Final report - Date: September 17, 2001, 16:00 local (22:00 UTC) - Place: Troy, MT - Coordinates: 48.315277, -115.986663 - Nearby events: https://openairdocs.org/map.md?lat=48.3153&lon=-115.9867&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report June 3, 2002 - Report: Approved by Office Director - Parties: U.S. Forest Service - NTSB case key (mKey): 53484 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA01TA172 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/53484/pdf - Page: https://openairdocs.org/ntsb/SEA01TA172 ## Probable cause The pilot-in-command's failure to maintain seperation/clearance from trees while maneuvering. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with object, maneuvering - aerial application - clearance - not maintained, pilot in command (cause) - object - tree(s) (contributing factor) ## Analysis The pilot was returning from an external load long-line firefighting flight when he noticed a vertical vibration above 90 knots. After landing at Troy he noticed damage to the main rotor blades. Subsequently, he noticed that pine needles had been ingested by the helicopter's induction system. The pilot reported that he had no memory of hitting any objects during the operation. The weather was clear with 20 miles visibility, and the sky was partially obscured by smoke. There was no report of mechanical failure or malfunction with the helicopter. ## Factual narrative On September 17, 2001, about 1600 mountain daylight time, a Bell 205 helicopter, N458CC, sustained substantial damage following a main rotor blade strike while conducting firefighting operations near Libby, Montana. The helicopter is registered to Billings Flying Service, Billings, Montana, and was being operated by the United States Forest Service (USFS) as a public use aircraft. The commercial pilot, the sole occupant of the helicopter, was not injured. Visual meteorological conditions prevailed, and USFS VFR flight following procedures were in effect. In a written statement dated September 26, 2001, the pilot reported that he was maneuvering near a shoreline in an effort to get a full bucket of water. "I made 40-50 bucket drops on the fire and flew out my fuel cycle before breaking off from the fire and returned to Troy Airport. On the return flight to Troy airport, I noticed a vertical vibration at approximately 90 knots (forward airspeed)." He continued to Troy airport at a slower speed to avoid the vibration. After landing without incident, the pilot noted damage to the helicopter's main rotor blades. He also noted that pine needles had been ingested into the aircraft's induction system. The pilot did not recall coming into contact with anything during the flight. Personnel from the USFS reported that the helicopter was conducting external load long-line (100 feet) operations when the helicopters main rotor blades contacted trees. Postaccident examination of the helicopter, by a certified mechanic, revealed that both main rotor blades sustained substantial damage. The pilot stated that the weather was clear with more than 20 miles visibility, with the sky partially obscured by occasional smoke. The pilot reported no mechanical failure or malfunction of the aircraft. ## Aircraft - Registration: [N458CC](https://openairdocs.org/aircraft/N458CC), registered now, S/N 67-17678, built 1967 (OpenAirDocs) - Reported make and model: Bell 205 - Registry model: [Williams Helicopter UH-1H](https://openairdocs.org/model/williams-helicopter-uh-1h) (registry code 9790870) (OpenAirDocs) - Registry engine: [Lycoming T53L-703](https://openairdocs.org/engine/lycoming-t53l-703) (registry code 41557, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 67-17678 - Airframe hours: 8668 - Engines: Allied Signal T-53-L-13B 1300 horsepower turbo shaft - Damage: Substantial damage - Flight: Public aircraft, Public use - Operator: U.S. Forest Service - Registered owner: Billings Flying Service - Airworthiness certificate: Special, Restricted (Special) - Last inspection: 100 hour, August 1, 2001, 37 hours before - Departed: 57S, Troy, MT - Destination: MT - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 55; injuries: none; commercial, flight instructor; medical: class 2, valid medical--w/ waivers/lim; last flight review August 29, 2001; seat: left; flight hours: 17,630 total, 3,530 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 315° at 10 knots - Visibility: 20 statute miles - Lowest ceiling: none - Temperature: 75 °F ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Incident 20010917024879I](https://openairdocs.org/incident/20010917024879I), Sep 17, 2001: Bell 205A, Troy, MT, Minor damage. (-23) The pilot stated he had flown for about 2 hours. After the flight, damage was noticed on the rotor blades. The pilot stated he was not aware of striking… 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.