NTSB CAROL · Event
Event LAX04CA321
Aircraft involved
Probable cause & findings
the CFI's failure to maintain an adequate airspeed and main rotor rpm, and his improper flare, which resulted in a hard landing. A factor in the accident was the CFI's diverted attention.
Factual narrative
On September 17, 2004, about 1445 Hawaiian standard time, a Robinson R22 Beta, N22XM, experienced a hard landing at the Kona International Airport, Kona, Hawaii. Hawaii Pacific Aviation was operating the helicopter under the provisions of 14 CFR Part 91. The certified flight instructor (CFI) and student pilot were not injured; the helicopter sustained substantial damage. The local instructional flight departed Kona about 1330. Visual meteorological conditions prevailed, and a flight plan had not been filed. In a written statement, the CFI stated that he and the student were both on the controls while executing a practice autorotation. As the helicopter's main rotor revolutions per minute (rpm) began to decrease, the CFI raised the collective in an effort to show the student a gentle and anticipated rpm drop. While the rpm needle moved to the bottom of the green arc, with the helicopter descending through about 200 feet above ground level (agl), he noticed that the airspeed had decreased to about 55 knots. He informed the student that they were going to execute a go-around procedure, because the airspeed should be at 65 knots when performing autorotations. The CFI further stated that the low rpm horn began to sound and he lowered the collective while pushing the carburetor heat control knob in the "off" position. Realizing that he did not adequately push the carburetor heat control knob down, the CFI leaned forward to look down at the exact knob position. While assessing the knob position, he felt the helicopter begin to settle and looked up at the instrument panel; he noted the rpm at 94 percent with the airspeed at 53 knots. With the ground approaching quickly, he flared the helicopter and subsequently opted to configure it in a level attitude because he feared that the tail boom would contact the surface first. The helicopter hit the surface hard and the main rotor severed the tail boom. The CFI stated that he did not know of any mechanical malfunctions or failures with the helicopter prior to impact. The helicopter experienced a hard landing, resulting in the main rotor blades severing the tail boom. While the certified flight instructor (CFI) and student pilot were executing a practice autorotation, the main rotor low revolutions per minute horn began to sound. He also realized that the airspeed had decreased 10 knots below the minimum speed for autorotations. The CFI lowered the collective while pushing the carburetor heat control knob in the "off" position. As the CFI leaned forward to assess the knob position, he felt the helicopter begin to settle. With the ground approaching quickly, he configured the helicopter it in a level attitude, fearing that if he flared, the tail boom would contact the surface first. The helicopter hit the surface hard and the main rotor severed the tail boom. The CFI stated that he did not know of any mechanical malfunctions or failures with the helicopter prior to impact. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12
Verbatim from NTSB's published report. Source file
NTSB_2004_LAX04CA321.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 (go-around). 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 2025 · Conference Paper
A Training Study to Improve Monitoring During A Go-Around
As part of an FAA program to improve go-around (GA) safety, we were asked to determine if we could improve the performance of the Pilot Monitoring (PM) during a GA maneuver.
- Flight Safety Foundation 2024 · FSF / AeroSafety World
Go-Around Safety Forum Findings
Foundation Go-Around Safety Forum technical findings — examines why pilots fail to execute go-arounds when criteria are met (stabilized approach gate not met, energy state out of envelope, traffic con…
- Semantic Scholar 2022 · Article (Journal of Safety Research)
Go-around accidents and general aviation safety.
INTRODUCTION Changes in General Aviation (GA) accident rates, specifically in the go-around phase, are examined by comparing the number of accidents, the proportion of fatal accidents, and the proport…
- Semantic Scholar 2021 · Article (Aerospace)
Classification and Analysis of Go-Arounds in Commercial Aviation Using ADS-B Data
Go-arounds are a necessary aspect of commercial aviation and are conducted after a landing attempt has been aborted. It is necessary to conduct go-arounds in the safest possible manner, as go-arounds …
- NASA NTRS 2021 · Accepted Manuscript (Version with final changes)
Go-Around Criteria Refinement for Transport Category Aircraft
Presently, airline pilots are trained to go around if, when lower than 500 ft above the ground, they are outside of a handful of parameters such as airspeed, position, and rate of descent.
- NASA NTRS 2019 · Conference Paper
Validation of Proposed Go-Around Criteria Under Various Environmental Conditions
This paper evaluates the effects of environmental conditions on touchdown performance under varying approach states and validates proposed go-around criteria developed using data from a previously con…
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