Aircraft Accident Report Crash During Takeoff of Carson Helicopters, Inc. Firefighting Helicopter Under Contract to the U.S. Forest Service Sikorsky S‐61N, N612AZ Near Weaverville, California August 5, 2008 Accident Report NTSB/AAR-10/06 National PB2010-910406 Transportation Safety Board NTSB/AAR-10/06 PB2010-910406 Notation 8066A Adopted December 7, 2010 Aircraft Accident Report Crash During Takeoff of Carson Helicopters, Inc., Firefighting Helicopter Under Contract to the U.S. Forest Service Sikorsky S‐61N, N612AZ Near Weaverville, California August 5, 2008 National Transportation Safety Board 490 L’Enfant Plaza, S.W. Washington, D.C. 20594 National Transportation Safety Board. 2010. Crash During Takeoff of Carson Helicopters, Inc., Firefighting Helicopter Under Contract to the U.S. Forest Service, Sikorsky S-61N, N612AZ, Near Weaverville, California, August 5, 2008. Aircraft Accident Report NTSB/AAR-10/06. Washington, DC. Abstract: This accident summary report discusses the August 5, 2008, accident involving a Sikorsky S-61N helicopter, N612AZ, which 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. The safety issues discussed in this report involve the accuracy of hover performance charts, USFS and Federal Aviation Administration (FAA) oversight, flight crew performance, accident survivability, weather observations at helispots, fuel contamination, flight recorder requirements, and certification of seat supplemental type certificates. Safety recommendations concerning these issues are addressed to the FAA and the USFS. The National Transportation Safety Board (NTSB) is an independent federal agency dedicated to promoting aviation, railroad, highway, marine, pipeline, and hazardous materials safety. Established in 1967, the agency is mandated by Congress through the Independent Safety Board Act of 1974 to investigate transportation accidents, determine the probable causes of the accidents, issue safety recommendations, study transportation safety issues, and evaluate the safety effectiveness of government agencies involved in transportation. The NTSB makes public its actions and decisions through accident reports, safety studies, special investigation reports, safety recommendations, and statistical reviews. Recent publications are available in their entirety on the Internet at <http://www.ntsb.gov>. Other information about available publications also may be obtained from the website or by contacting: National Transportation Safety Board Records Management Division, CIO-40 490 L’Enfant Plaza, SW Washington, DC 20594 (800) 877-6799 or (202) 314-6551 NTSB publications may be purchased, by individual copy or by subscription, from the National Technical Information Service. To purchase this publication, order report number PB2010-910406 from: National Technical Information Service 5285 Port Royal Road Springfield, Virginia 22161 (800) 553-6847 or (703) 605-6000 The Independent Safety Board Act, as codified at 49 U.S.C. Section 1154(b), precludes the admission into evidence or use of NTSB reports related to an incident or accident in a civil action for damages resulting from a matter mentioned in the report. NTSB Aircraft Accident Report Contents Figures ........................................................................................................................................... iv Tables ..............................................................................................................................................v Abbreviations and Acronyms ..................................................................................................... vi Executive Summary .......................................................................................................................x 1. The Accident ..........................................................................................................................1 1.1 History of the Flight ................................................................................................................1 1.2 Injuries to Persons ...................................................................................................................9 1.3 Damage to Aircraft .................................................................................................................9 1.4 Other Damage .........................................................................................................................9 1.5 Personnel Information .............................................................................................................9 1.5.1 The Pilot-in-Command ..................................................................................................9 1.5.2 The Copilot ..................................................................................................................10 1.5.3 The Inspector Pilot .......................................................................................................11 1.6 Aircraft Information ..............................................................................................................11 1.6.1 Airframe Fuel System ..................................................................................................13 1.6.2 Engine Information ......................................................................................................13 1.6.2.1 Explanation of Topping ................................................................................15 1.6.2.2 Power Assurance Checks ..............................................................................16 1.6.2.3 Engine Fuel System ......................................................................................17 1.6.2.4 Stator Vane Operation...................................................................................20 1.6.3 Type Certificate and Supplemental Type Certificates .................................................22 1.6.3.1 Overview .......................................................................................................22 1.6.3.2 Carson Helicopters’ Position on Use of RFMS #6, #7, and #8 ....................23 1.6.3.3 FAA Position on Use of RFMS #6, #7, and #8 ............................................24 1.6.4 Weight and Balance .....................................................................................................25 1.6.4.1 Grants Pass January 4, 2008, Weight and Balance Charts ...........................26 1.6.4.2 Perkasie January 4, 2008, Weight and Balance Charts .................................27 1.6.4.3 Estimated Empty Weight at Accident ...........................................................28 1.6.4.4 Weight and Balance Charts for Other Carson Helicopters’Aircraft .............30 1.6.5 Performance Charts ......................................................................................................31 1.6.5.1 RFMS #8 Figure 4, Takeoff Power Available ..............................................33 1.6.5.2 Use of Above-Minimum Specification Torque ............................................36 1.6.5.3 Load Calculations .........................................................................................37 1.7 Meteorological Information ..................................................................................................38 1.7.1 Automated Weather Observations ...............................................................................38 1.7.2 Weather Observations from Other Sources .................................................................39 1.8 Aids to Navigation ................................................................................................................41 1.9 Communications ...................................................................................................................41 1.10 Airport Information ...............................................................................................................41 i NTSB Aircraft Accident Report 1.11 Flight Recorders ....................................................................................................................41 1.11.1 FDR Carriage Requirements .....................................................................................42 1.12 Wreckage and Impact Information .......................................................................................42 1.13 Medical and Pathological Information ..................................................................................45 1.14 Fire ........................................................................................................................................46 1.15 Survival Aspects ...................................................................................................................46