NTSB CAROL · Event
Event LAX99LA166
Registry · N6148V
FAA Aircraft Registry record.
Make / Model
SCHWEIZER 269C-1
Year of manufacture
1998 · 1 years old at event
TCDS
4H12 · SCHWEIZER RSG LLC
Engine
LYCOMING HO-360 (180 hp)
Seats / Engines
3 seats · 1 engine
Last airworthiness date
19980914
ADS-B equipped
Yes — Mode-S A8011E
Registrant of record
CHUPP AARON
Source: FAA Aircraft Registry (releasable master file).
Aircraft involved
Probable cause & findings
The inadequate supervision of the student pilot by the flight instructor during the practice autorotation, which resulted in a delayed flare and the tail rotor contacting the ground. A factor was a misinterpreted communication between the flight instructor and student.
Factual narrative
On April 30, 1999, at 0917 hours Pacific daylight time, a Schweizer 269C-1 helicopter, N6148V, impacted the ground and severed the tail boom during a practice autorotation landing at the Concord, California, airport. The helicopter, operated by Helicopter Adventures, Inc., Concord, sustained substantial damage. The commercial licensed flight instructor and student pilot were not injured. The local instructional flight was conducted under 14 CFR Part 91 and originated at the Concord airport about 0830. Visual meteorological conditions prevailed and no flight plan was filed. The flight instructor reported that he and the student were practicing straight-in autorotations with power recoveries. During the first four autorotations, the student was the primary manipulator of the controls. The instructor reported that the student was initiating the flare too high, so he told the student that they would do the next approach together with both of them on the controls. During the flare portion of the autorotation, the stinger struck the runway surface. The tail rotor then contacted the surface and the helicopter began to yaw to the right. The instructor rolled the throttle off after about 90 degrees of right yaw and entered a hovering autorotation. The helicopter ultimately yawed 360 degrees to the right and the landing gear skids contacted the ground with the aircraft coming to rest approximately 100 feet from the point where the tail rotor struck the runway. The main rotor severed the tail boom. The flight instructor stated that he had intended for the student to initiate the flare, and he planned just to follow through on the controls to guide him to flare a little lower than on the previous attempts. He reported that he believes that the student interpreted his instructions to mean that he (the instructor) would be making the primary inputs. The flight instructor reported that the accident could have been prevented through "better communication between student and instructor as to who is responsible for initiating a control input during all phases of flight and especially during critical phases." The flight instructor and student were practicing straight-in autorotations with power recoveries. During the first four autorotations, the student was the primary manipulator of the controls. The student was initiating the flare too high and so the instructor told the student that they would do the next approach together with both of them on the controls. During the flare portion of the ensuing autorotation, the stinger struck the runway surface. The tail rotor then contacted the surface and the helicopter yawed 360 degrees to the right and came to rest approximately 100 feet where the tail rotor struck the runway. The main rotor severed the tail boom. The instructor reported that he believed that the student misinterpreted his instructions to mean that he (the instructor) would be making the primary control inputs, whereas, he had intended for the student to make control inputs to initiate the flare. He planned just to follow through on the controls to guide the student to flare a little lower than on the previous attempts. The flight instructor stated that the accident could have been prevented through 'better communication between student and instructor as to who is responsible for initiating a control input during all phases of flight and especially during critical phases.' Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12
Verbatim from NTSB's published report. Source file
NTSB_1999_LAX99LA166.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.
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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 ↗