Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Weaverville, California 96093
Tuesady, August 5, 2008 19:41 PDT
NTSB Narrative Summary Released at Completion of Accident
The Safety Board's full report is available at http://www.ntsb.gov/publictn/A_Acc1.htm. The Aircraft Accident Report number is NTSB/AAR-10-06.
On August 5, 2008, about 1941 Pacific daylight time, a Sikorsky S-61N helicopter, N612AZ, impacted trees and terrain during the initial climb after takeoff from Helispot 44 (H-44), located at an elevation of about 6,000 feet in mountainous terrain near Weaverville, California. The pilot-in-command, the safety crewmember, and seven firefighters were fatally injured; the copilot and three firefighters were seriously injured. Impact forces and a postcrash fire destroyed the helicopter, which was being operated by the U.S. Forest Service (USFS) as a public flight to transport firefighters from H-44 to another helispot. The USFS had contracted with Carson Helicopters, Inc. (CHI) of Grants Pass, Oregon, for the services of the helicopter, which was registered to CHI and leased to Carson Helicopter Services, Inc. of Grants Pass. Visual meteorological conditions prevailed at the time of the accident, and a company visual flight rules flight plan had been filed.
NTSB Probable Cause Narrative
The following actions by Carson Helicopters: 1) the intentional understatement of the helicopter's empty weight, 2) the alteration of the power available chart to exaggerate the helicopter's lift capability, and 3) the practice of using unapproved above-minimum specification torque in performance calculations that, collectively, resulted in the pilots relying on performance calculations that significantly overestimated the helicopter's load-carrying capacity and did not provide an adequate performance margin for a successful takeoff; and insufficient oversight by the U.S. Forest Service and the Federal Aviation Administration.
Contributing to the accident was the failure of the flight crewmembers to address the fact that the helicopter had approached its maximum performance capability on their two prior departures from the accident site because they were accustomed to operating at the limit of the helicopter’s performance.
Contributing to the fatalities were the immediate, intense fire that resulted from the spillage of fuel upon impact from the fuel tanks that were not crash resistant, the separation from the floor of the cabin seats that were not crash resistant, and the use of an inappropriate release mechanism on the cabin seat restraints.
Event Information
| Type of Event | Accident |
| Event Date | 8/5/2008 |
| Event Day of the Week | Tuesday |
| Time of Event | 1941 |
| Event Time Zone | Pacific Daylight Time |
| Event City | Weaverville |
| Event State | CALIFORNIA |
| Event Country | -- |
| Zipcode of the event site | 96093 |
| Event Date Year | 2008 |
| Event Date Month | 8 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 405451N |
| Event Location Longitude | 1231509W |
| Event Location Airport | -- |
| Event Location Nearest Airport ID | -- |
| Indicates whether the acc/inc occurred off or on an airport | -- |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | -- |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | RDD |
| Elevation of weather observation facility | -- |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | -- |
| Lighting Conditions | -- |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | 1700 |
| Sky/Lowest/Cloud Conditions | Thin Broken |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 33 |
| Dew Point at event time (in degress fahrenheit) | 2 |
| Wind Direction (degrees magnetic) | 150 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 7 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | -- |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 29.83 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | Fatal |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | 9 |
| Injury Total Minor | -- |
| Injury Total None | -- |
| Injury Total Serious | 4 |
| Injury Total All | 13 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 27951 |
| NTSB Notification Source | U.S. Forest Service |
| NTSB Notification Date | Aug 5 2008 12:00AM |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Jan 20 2011 1:55PM |
| User who most recently changed record | broda |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | Washington, D.C., AAI-100 |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N612AZ |
| NTSB Number | LAX08PA259 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Public Use |
| Type of Flight Plan filed | Company VFR |
| Flight plan Was Activated? | -- |
| Damage | Destroyed |
| Aircraft Fire | Ground |
| Aircraft Explosion | -- |
| Aircraft Manufacturer's Full Name | SIKORSKY |
| Aircraft Model | S-61N |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | -- |
| Certified Max Gross Weight | -- |
| Aircraft Category | Helicopter |
| Aircraft Registration Class | -- |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | -- |
| Number of Engines | -- |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | -- |
| Date of Last Inspection | -- |
| Airframe hours since last inspection | -- |
| Airframe Hours | -- |
| ELT Installed | Unknown |
| ELT Activated | Unknown |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | -- |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | -- |
| Aircraft Owner State | -- |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | -- |
| Operator is an individual? | No |
| Operator Name | USDA Forest Service |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | -- |
| Operator City | Boise |
| Operator State | ID |
| Operator Country | USA |
| Operator Zip code | 83705 |
| Operator Code | -- |
| Owner has at least one certificate | None |
| Other Operator of large aircraft? | No |
| Certified for Part 133 or 137 Operation | -- |
| Operator Certificate Number | -- |
| Indicates whether an air carrier operation was scheduled or not | -- |
| Indicates Domestic or International Flight | -- |
| Operator carrying Pax/Cargo/Mail | -- |
| Type of Flying (Per_Bus / Primary) | -- |
| Second Pilot on Board | -- |
| Departure Point Same as Event | Yes |
| Departure Airport Code | NONE |
| Departure City | Weaverville |
| Departure State | CA |
| Departure Country | USA |
| Departure Time | 1940 |
| Departure Time Zone | PDT |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | NONE |
| Destination City | -- |
| Destination State | -- |
| Destination Country | USA |
| Specific Phase of Flight | Takeoff - initial climb |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 20 2011 1:50PM |
| User who most recently changed record | broda |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | -- |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |