ANC98TA011
1997-12-05 · ANCHORAGE, Alaska, United States · None · 1 aircraft · Status: Completed
Airport CSR
Aircraft involved
Probable cause & findings
The pilot's failure to maintain adequate rotor RPM during an autorotation landing.
Factual narrative
On December 5, 1997, about 1120 Alaska standard time, a Bell 206B helicopter, N83146, sustained substantial damage during a practice autorotation landing at the Campbell Airstrip, Anchorage, Alaska. The helicopter was being operated as a visual flight rules (VFR) local area government proficiency flight under Title 14 CFR Part 91, when the accident occurred. The helicopter is registered to, and operated by, the State of Alaska. The first pilot, seated in the right seat, and the second pilot, seated in the left seat, both certificated commercial pilots, were not injured. Visual meteorological conditions prevailed. The flight originated at Merrill Field, Anchorage, Alaska, at 1030. The first pilot, a Fish and Wildlife Protection Officer, and the second pilot, a pilot for the Alaska State Troopers, reported they were performing practice touchdown autorotation landings to maintain their proficiency. The first pilot had performed several, straight-in, touchdown autorotations to snow covered terrain. During the last autorotation, the first pilot entered the autorotation at 800 feet above the ground, and about 80 knots. He indicated during the descent he maintained a 65 knot airspeed, and began a deceleration flare about 50 to 60 feet above the ground. As the ground speed dissipated, the pilot leveled the helicopter, applied main rotor collective pitch, and touched down with about a 30 foot ground run. As the helicopter slowed to a stop, the pilot indicated the helicopter shuddered several times. Examination of the helicopter after landing revealed the main rotor blades struck the tail boom. The tail assembly, consisting of the horizontal and vertical stabilizer, and the tail rotor assembly, was severed from the tail boom. Two commercial pilots were practicing touchdown autorotation landings at a private snow covered airstrip. The purpose of the flight was for both pilots to maintain their proficiency. The first pilot had performed several straight-in touchdown autorotations. During the last autorotation, the first pilot entered the autorotation at 800 feet above the ground and about 80 knots. During the descent, the pilot maintained a 65 knot airspeed, and began a deceleration flare about 50 to 60 feet above the ground. As the ground speed dissipated, the pilot leveled the helicopter, applied main rotor collective pitch, and touched down with about a 30 foot ground run. As the helicopter slowed to a stop, the pilot indicated the helicopter shuddered several times. The main rotor blades struck the tail boom, severing the horizontal and vertical stabilizer, and the tail rotor assembly, from the tail boom. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12
Verbatim from NTSB's published report. Source file
NTSB_1997_ANC98TA011.txt.
Findings + structured fields enriched from FAA avall.mdb.
Full investigation docket on
data.ntsb.gov ↗.
Search this event elsewhere
External sources are reported, not agency: signal that something happened, not fact about what happened.
- TallyAero Live Wire Aviation press
- NTSB CAROL Agency ↗
- NTSB Docket Agency ↗
- Aviation Safety Network Aviation press ↗
- Kathryn's Report Aviation press ↗
- Aviation Herald Aviation press ↗
- AVweb Aviation press ↗
- Pilots of America Community ↗
- Reddit /r/flying Community ↗
- FlightAware Aviation press ↗
- AOPA accident database Aviation press ↗
- Google News News ↗
- DuckDuckGo News ↗
Related research
Matched on aircraft type or causal vocabulary (icing). All research papers
- arXiv 2026 · arXiv preprint Enabling Beyond-Visual-Line-of-Sight Drones Operation over Open RAN 5G Networks with Slicing
Among the foretold claims of the transition from 5G to 6G, Beyond-Visual-Line-of-Sight (BVLoS) drone operation has emerged as a prominent Internet-of-Robots enabler.
- NASA NTRS 2026 · Contractor Report (CR) Icing Physics Studies Using the 3D SIDRM Test Article: 2023 Icing Tests Analysis
In-flight icing is an important safety issue and is a factor that affects aircraft design and performance. Newer regulations are driving a need for improvements in airframe and engine icing simulation…
- arXiv 2025 · arXiv preprint Multi-Agent Deep Reinforcement Learning for UAV-Assisted 5G Network Slicing: A Comparative Study of MAPPO, MADDPG, and MADQN
The growing demand for robust, scalable wireless networks in the 5G-and-beyond era has led to the deployment of Unmanned Aerial Vehicles (UAVs) as mobile base stations to enhance coverage in dense urb…
- NASA NTRS 2025 · Presentation NASA Icing Update – March 2025
This NASA Icing Update was prepared for presentation to the SAE International AC-9C Inflight Icing Technology Committee. This update includes the following topics: planned Rotational Icing Scaling tes…
- Embry-Riddle Scholarly Commons 2025 · Journal article (JAAER) A Mathematical Model on the Temporal Dynamics of Aviation Competitive Pricing
This study investigates the competitive dynamics of airport pricing using U.S. airport data to validate the findings. It employs linear and nonlinear ordinary differential equation models to analyze t…
- arXiv 2024 · arXiv preprint An energy-stable phase-field model for droplet icing simulations
A phase-field model for three-phase flows is established by combining the Navier-Stokes (NS) and the energy equations, with the Allen-Cahn (AC) and Cahn-Hilliard (CH) equations and is demonstrated ana…