NTSB CAROL · Event
Event SEA99LA033
Aircraft involved
Probable cause & findings
The dual student's improper touchdown while drifting during a practice autorotation. Contributing to the accident was the flight instructor (CFI) inadequate remedial action.
Factual narrative
On February 15, 1999, about 1000 pacific standard time, a Robinson R-22, N8362Q, registered to a private owner and operated by Classic Helicopter Corporation as a 14 CFR 91 local instructional flight, was substantially damaged after it collided with the ground while maneuvering at Boeing Field/King County International Airport, Seattle, Washington. Visual meteorological conditions prevailed and no flight plan was filed. The certified flight instructor received minor injuries and the student pilot was uninjured. There was no fire and no report of an ELT actuating. The flight originated from the Boeing Field airport approximately one hour and thirty minutes prior to the accident. During an interview and subsequent written statement, the flight instructor reported that for the first time in the training program, the student was practicing hovering autorotations. The flight instructor stated that he demonstrated approximately three of the maneuvers. During the fourth maneuver, both he and the student were on the controls. The flight instructor stated that he slowly rolled off the throttle and the helicopter started to drift to the left and descend. The left landing skid caught the grass and the helicopter began to roll to the left. The flight instructor stated that before he could recover, the helicopter rolled over onto its side. No evidence was found to indicate a mechanical failure or malfunction. During an interview and subsequent written statement, the flight instructor reported that for the first time in the training program, the student was practicing hovering autorotations. The flight instructor stated that he demonstrated approximately three of the maneuvers. During the fourth maneuver, both he and the student were on the controls. The flight instructor stated that he slowly rolled off the throttle and the helicopter started to drift to the left and descend. The left landing skid caught the grass and the helicopter began to roll to the left. The flight instructor stated that before he could recover, the helicopter rolled over onto its side. No evidence was found to indicate a mechanical failure or malfunction. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12
Verbatim from NTSB's published report. Source file
NTSB_1999_SEA99LA033.txt.
Findings + structured fields enriched from FAA avall.mdb.
Full investigation docket on
data.ntsb.gov ↗.
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Related research
What the literature says.
Academic papers and agency reports matching this event's aircraft type or causal vocabulary (icing). Sourced from NASA NTRS, NTSB Safety Studies, FAA CAMI, AOPA Air Safety Institute, Embry-Riddle Scholarly Commons, arXiv, and the Semantic Scholar academic graph.
- 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…
- 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…
- 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…
- 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…
- NASA NTRS 2024 · Presentation
NASA Icing Update – Oct 2024
This presentation provides a status update on select NASA icing research activities for the SAE AC-9C Icing Technical Committee Meeting on Oct 21, 2024.
Browse the full corpus — academia portal ↗