NTSB CAROL · Event
Event GAA17CA562
Aircraft involved
Probable cause & findings
The pilot under evaluation’s failure to maintain adequate airspeed during a simulated hydraulic failure, which resulted in a loss of helicopter control. Contributing to the accident was the check pilot’s delayed remedial action.
Factual narrative
The check pilot reported that he was administering an annual standardization check ride in the public use helicopter. The last maneuver evaluated was a hydraulic failure that would terminate by accomplishing a simulated run-on landing. The maneuver was initiated when the check/evaluated pilot established an out of ground effect (OGE) hover on the downwind leg of the pattern. The check-pilot engaged the hydraulic test button on the center console to "simulate a hydraulic failure." The evaluated pilot lowered the nose and established forward airspeed to maintain aircraft controllability. He maintained stabilized forward flight on the downwind leg, and the check-pilot disengage the hydraulic test button. The check pilot moved the hydraulic cut off switch to the off position, and the hydraulic system was disengaged. The evaluated pilot remained on the controls and established a shallow approach until about 3ft above the runway. Over the runway, the evaluated pilot allowed the helicopter's airspeed to decrease, and the check-pilot stated, "Keep the speed up." The evaluated pilot responded by lowering the nose, however, an uncontrollable rapid left yaw ensued. The check-pilot took control of the helicopter and attempted to keep the helicopter over the runway, but the nose pitched down, and the main rotor blades struck the ground. The check pilot decreased the fuel control and the helicopter settled upright on the runway. The helicopter sustained substantial damage to the windscreen above the cabin, the tailboom and tail rotor drive system. The METAR at the accident airport during the time of the accident reported that the wind from 250° at 3kts, the skies were clear, and the temperature was 72°F. According to the Operator's Flight Manual: In case of loss of hydraulic pressure, the recommended safety speed range is from 40 to 60 kt. CAUTION: DO NOT ATTEMPT TO CARRY OUT HOVER FLIGHT OR ANY LOW SPEED MANEUVER WITHOUT HYDRAULIC PRESSURE ASSISTANCE. THE INTENSITY AND DIRECTION OF THE CONTROL FEEDBACK FORCES WILL CHANGE RAPIDLY. THIS WILL RESULT IN EXCESSIVE PILOT WORKLOAD, POOR AIRCRAFT CONTROL, AND POSSIBLE LOSS OF CONTROL. There were no mechanical malfunctions or anomalies that were identified as a result of this investigation. The check pilot reported that he was administering an annual standardization check ride in the public helicopter. The last maneuver evaluated was a hydraulic failure that would terminate by accomplishing a simulated run-on landing. The maneuver was initiated when the evaluated pilot established an out-of-ground-effect (OGE) hover on the downwind leg of the pattern. The check pilot engaged the hydraulic test button on the center console to "simulate a hydraulic failure." The evaluated pilot lowered the nose and established forward airspeed to maintain controllability. He maintained stabilized forward flight on the downwind leg, and the check pilot disengaged the hydraulic test button. The check pilot moved the hydraulic cutoff switch to the "off" position, and the hydraulic system was disengaged. The evaluated pilot remained on the controls and established a shallow approach until about 3 ft above the runway. Over the runway, the evaluated pilot allowed the helicopter's airspeed to decrease, and the check pilot stated, "Keep the speed up." The evaluated pilot responded by lowering the nose; however, an uncontrollable rapid left yaw ensued. The check pilot took control of the helicopter and attempted to keep the helicopter over the runway, but the nose pitched down, and the main rotor blades struck the ground. The check pilot decreased the fuel control, and the helicopter settled upright on the runway. The helicopter sustained substantial damage to the windscreen above the cabin, the tailboom, and tail rotor drive system. The METAR at the accident airport reported that, at the time of the accident, the wind from 250° at 3 knots, the skies were clear, and the temperature was 72°F. According to the Operator's Flight Manual: In case of loss of hydraulic pressure, the recommended safety speed range is from 40 to 60 kt. CAUTION: DO NOT ATTEMPT TO CARRY OUT HOVER FLIGHT OR ANY LOW SPEED MANEUVER WITHOUT HYDRAULIC PRESSURE ASSISTANCE. THE INTENSITY AND DIRECTION OF THE CONTROL FEEDBACK FORCES WILL CHANGE RAPIDLY. THIS WILL RESULT IN EXCESSIVE PILOT WORKLOAD, POOR AIRCRAFT CONTROL, AND POSSIBLE LOSS OF CONTROL. Postaccident examination revealed no mechanical malfunctions or anomalies that would have precluded normal operation. Source: NTSB Aviation Accident Database Retrieved: 2026-02-12
NTSB Findings
Hierarchical cause / factor breakdown from the FAA bulk avdata database. Each finding tagged C (Cause) or F (Factor).
- C Personnel issues-Task performance-Use of equip/info-Aircraft control-Pilot - C
- C Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Airspeed-Not attained/maintained - C
- F Personnel issues-Action/decision-Action-Delayed action-Instructor/check pilot - F
Verbatim from NTSB's published report. Source file
NTSB_2017_GAA17CA562.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 (loss of control). Sourced from NASA NTRS, NTSB Safety Studies, FAA CAMI, AOPA Air Safety Institute, Embry-Riddle Scholarly Commons, arXiv, and the Semantic Scholar academic graph.
- Embry-Riddle Scholarly Commons 2025 · Journal article (JAAER)
A Scoping Review of Aviation Loss of Control Inflight Research
Loss of control – inflight (LOC-I) contributes to aircraft accidents at unacceptably high rates. Significant industry efforts and research have aimed to improve LOC-I prevention, detection, and recove…
- SKYbrary (Eurocontrol) 2024 · SKYbrary article
Loss of Control In-Flight (LOC-I) — SKYbrary Knowledge Base
SKYbrary comprehensive knowledge-base entry on Loss of Control In-Flight — definitions, contributing factors, accident case studies (Air France 447, Colgan 3407), and prevention strategies.
- NTSB Aircraft Accident Reports 2022 · Accident report
Loss of Control on Takeoff in Icing Conditions — Citation 560XL
Cessna Citation 560XL fatal takeoff icing accident, March 2018. Investigation of a Citation 560XL loss-of-control takeoff accident in icing conditions.
- Semantic Scholar 2021 · Article (Aviation)
ANALYSIS OF GENERAL AVIATION FIXED-WING AIRCRAFT ACCIDENTS INVOLVING INFLIGHT LOSS OF CONTROL USING A STATE-BASED APPROACH
Inflight loss of control (LOC-I) is a significant cause of General Aviation (GA) fixed-wing aircraft accidents. The United States National Transportation Safety Board’s database provides a rich source…
- NASA NTRS 2021 · Presentation
Use of Design of Experiments in Determining Neural Network Architectures for Loss of Control Detection
Abstract—We describe empirical methods for selecting a neural network architecture to implement belief state inference on generic commercial transport aircraft.
- NASA NTRS 2021 · Conference Paper
Use of Design of Experiments in Determining Neural Network Architectures for Loss of Control Detection
We describe empirical methods for selecting a neural network architecture to implement belief state inference on generic commercial transport aircraft.
Browse the full corpus — academia portal ↗