NTSB CAROL · Event
Event SEA00LA156
Aircraft involved
Probable cause & findings
An inadequately planned approach. The encounter of wake turbulence and not being able to maintain aircraft control were factors.
Factual narrative
On August 9, 2000, at 1832 Pacific daylight time, a Cessna 152, N6434H, registered to and operated by Hillsboro Aviation as a 14 CFR Part 91 instructional flight, collided with the ground short of the runway 02 at Hillsboro, Oregon. Visual meteorological conditions prevailed at the time and no flight plan was filed for the local flight. The aircraft was substantially damaged. The flight instructor was seriously injured, while the student pilot received minor injuries. The student pilot reported that the aircraft was trailing about 30 seconds behind two Life Flight helicopters (Bell 230 and BK 117) on final approach to runway 02. After the helicopters crossed over the airport boundary fence (about 500 feet before the end of the runway) they made a right turn for landing on the ramp. The student stated that he was on the controls at the time, and at about 100-150 feet above ground level and 60 knots, the aircraft suddenly rolled to the right about 90 degrees. The flight instructor took over the controls and righted the aircraft, however, it continued to settle to the ground in a nose down attitude. The aircraft collided with the ground about 200 feet short of the end of the runway and slid about 60 feet before coming to rest. In a written statement that was attached to the NTSB Pilot/Operator Aircraft Accident Report Form 6120.1/2, which was signed by the school director from Hillsboro Aviation, it indicated that, "It is believed wake turbulence from the helicopters may have contributed to the accident." The Federal Aviation Administration Inspector from the Portland-Hillsboro Flight Standards District Office responded to the accident site. The inspector reported that control continuity was established throughout the flight control system. No evidence of a mechanical failure or malfunction was found. The student pilot reported that the airplane was trailing about 30 seconds behind two Life Flight helicopters on final approach for landing. About 500 feet before the end of the runway, the helicopters turned to the right toward the ramp area. The student pilot, who was on the flight controls at the time, stated that the approach was continued and at about 100-150 feet AGL and 60 knots airspeed, the airplane suddenly rolled to the right about 90 degrees. The flight instructor took over the controls and righted the aircraft, however, it continued to settle to the ground in a nose down attitude. The airplane collided with the ground about 200 feet short of the end of the runway and slid about 60 feet before coming to rest. Inspection of the flight control system did not reveal a mechanical failure or malfunction. The operator of the aircraft stated that he believed that wake turbulence from the helicopters contributed to the aircraft's sudden roll and subsequent collision with the ground. Source: NTSB Aviation Accident Database (Pre-2008 Archive) Retrieved: 2026-02-12
Verbatim from NTSB's published report. Source file
NTSB_2000_SEA00LA156.txt.
Findings + structured fields enriched from FAA avall.mdb.
Full investigation docket on
data.ntsb.gov ↗.
Beyond the agency record
Search this event elsewhere.
Pre-filled searches into the sources where news + community discussion of aviation events lives. External sources are reported, not agency. Treat them as signal that something happened, not as fact about what happened.
Entity-clustered aviation events in the press — last 24 hr + 30-day archive.
Official agency record + docket.
Investigative docket: factual reports, photos, transcripts.
Long-running aviation incident database (Flight Safety Foundation).
Community NTSB synthesis blog — often has photos and witness reports.
Gold-standard aviation incident blog.
Aviation industry news search.
GA pilot forum — informed but rumor-prone.
GA pilot subreddit search.
Tail-number page — flight history (free tier limited).
AOPA Air Safety Institute search.
Mainstream press coverage. Recent events only.
Privacy-preserving news search.
External links open in a new tab. We don't ingest their content; we deep-link search queries.
Related research
What the literature says.
Academic papers and agency reports matching this event's aircraft type or causal vocabulary (wake turbulence, turbulence). 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 2019 · Conference Paper
Aircraft wake turbulence minimization by aerodynamic means
The paper reviews NASA's efforts on wake vortex turbulence minimization by aerodynamic design or retrofit modifications to large transport aircraft.
- NASA NTRS 2019 · Conference Paper
Wake Turbulence Mitigation for Arrivals (WTMA)
The preliminary Wake Turbulence Mitigation for Arrivals (WTMA) concept of operations is described in this paper. The WTMA concept provides further detail to work initiated by the Wake Vortex Avoidance…
- NASA NTRS 2019 · Conference Paper
Aircraft wake turbulence avoidance
Aircraft wake turbulence /trailing vortex systems/ avoidance during flight, describing procedures for pilots and tower operators
- NASA NTRS 2019 · Conference Paper
Aircraft wake turbulence progress and plans
Aircraft wake turbulence and trailing vortices, investigating physical characteristics, hazard potential and avoidance techniques
- SKYbrary (Eurocontrol) 2023 · SKYbrary article
Wake Vortex Turbulence — SKYbrary Knowledge Base
SKYbrary wake vortex turbulence comprehensive article — generation mechanics, dissipation factors, separation standards (ICAO LIGHT/MEDIUM/HEAVY/SUPER + recategorisation RECAT-EU).
- NASA NTRS 2019 · Contractor Report (CR)
An Examination of Aviation Accidents Associated with Turbulence, Wind Shear and Thunderstorm
The focal point of the study reported here was the definition and examination of turbulence, wind shear and thunderstorm in relation to aviation accidents.
Browse the full corpus — academia portal ↗