ERA10TA501
2010-09-24 · Covington, Georgia, United States · Minor · 1 aircraft · Status: Completed
Airport 9A1
Current FAA registration · N91DK
- Make / Model
- EUROCOPTER AS 350 B2
- Year of manufacture
- 2005 · 5 years old at event
- Engine
- TURBOMECA ARRIEL 1D1 (712 hp)
- Seats / Engines
- 6 seats · 1 engine
- Last airworthiness date
- 20050820
- ADS-B equipped
- Yes — Mode-S AC94A7
Source: FAA Aircraft Registry (releasable master file).
Aircraft involved
Probable cause & findings
The flight instructor's loss of control of the helicopter during the intentional demonstration of a low speed, hydraulics-off maneuver, that was warned against in the helicopter manufacturer's flight manual.
Factual narrative
On September 24, 2010, at 1634 eastern daylight time, an American Eurocopter AS-350B2, N91DK, operated by the Dekalb County Police, was substantially damaged after a loss of control while landing at Covington Airport (9A1), Covington, Georgia. The certificated commercial pilot and the certificated flight instructor sustained minor injuries. Visual meteorological conditions prevailed, and no flight plan was filed for the local public use instructional flight. The flight instructor reported to witnesses, police, and to a Federal Aviation Administration (FAA) inspector that he and the pilot had been performing hydraulics-off maneuvers, the helicopter "got away from them," and control could not be regained prior to ground contact. According to the pilot, he was conducting recurrent training with the instructor, a contractor, who was not affiliated with the Dekalb County Police. He said they had returned from a meal break, and that this was the second flight of the day. According to the pilot, the instructor simulated a hydraulics failure by "turning off" the flight control hydraulics switch, and he was to then perform a hydraulics-off, run-on landing as the remedial action to the simulated emergency. As the helicopter slowed over the runway, the nose yawed to the left, and the pilot was unable to correct the yaw with right pedal input. The instructor announced and took control of the helicopter, and completed a low-level, left-hand orbit to demonstrate and complete the maneuver. According to the pilot, as the helicopter completed the left orbit and lined up for landing, it "rolled wings level" but then continued to roll to the right and collided with terrain. He said that the entire maneuver was conducted hydraulics-off, and that he felt the instructor had control of the helicopter until it rolled past wings-level to the right. The pilot added that the instructor had successfully completed a similar maneuver earlier in the day, without restoring the flight control hydraulics. Both the pilot and the instructor stated that there was nothing wrong with the performance and handling of the helicopter. The pilot held a commercial pilot certificate with a rating for rotorcraft helicopter. His most recent FAA second class medical certificate was issued July 14, 2010. The pilot reported 929 total hours of flight experience, of which 929 hours were in the accident helicopter make and model. The flight instructor held a commercial pilot certificate with ratings for airplane single engine, multiengine, rotorcraft-helicopter, and instrument airplane and helicopter. He held a flight instructor certificate for airplane single engine, rotorcraft-helicopter, and instrument airplane and helicopter. His most recent FAA second class medical certificate was issued April 12, 2010. The instructor reported 4,100 total hours of flight experience on that date. According to the operator, the helicopter had accrued 3,158 total aircraft hours. Its most recent 100-hour inspection was completed on August 12, 2010, at 3,100 total aircraft hours. At 1650, the weather reported at LZU, 21 miles north of the site, included scattered clouds at 5,500 feet and winds from 200 degrees at 5 knots. The visibility was 10 miles. The temperature was 32 degrees Celsius (C) and the dew point was 21 degrees C. The altimeter setting was 30.09 inches of mercury. Examination of the helicopter by an FAA inspector revealed the helicopter sustained substantial damage to cockpit, cabin structure, and landing gear. According to the Eurocopter AS 350 B2 Flight Manual (Emergency Procedures) and Flight Manual Supplement, Hydraulic Pressure Failure Training Procedures, "CAUTION: DO NOT ATTEMPT TO CARRY OUT HOVER FLIGHT OR ANY LOW SPEED MANEUVER WITHOUT HYDRAULIC PRESSSURE 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." According to the pilot of the helicopter, the instructor simulated a hydraulics failure by “turning off” the flight control hydraulics switch, in order to perform a hydraulics-off, run-on landing as the remedial action to the simulated emergency. As the helicopter slowed over the runway, the nose yawed to the left, and the pilot was unable to correct the yaw with right pedal input. The instructor took control of the helicopter, and completed a low-level, left-hand orbit to demonstrate and complete the maneuver. As the helicopter completed the left orbit and lined up for landing, it “rolled wings level” but then continued to roll to the right and collided with terrain. The pilot said that the entire maneuver was conducted hydraulics-off, and that he felt the instructor had control of the helicopter until it rolled past wings-level to the right. The pilot added that the instructor had successfully completed a similar maneuver earlier in the day, without restoring the flight control hydraulics. According to the manufacturer's Flight Manual (Emergency Procedures) and the Flight Manual Supplement, Hydraulic Pressure Failure Training Procedures, "CAUTION: DO NOT ATTEMPT TO CARRY OUT HOVER FLIGHT OR ANY LOW SPEED MANEUVER WITHOUT HYDRAULIC PRESSSURE 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." Both the pilot and the instructor stated that there was nothing wrong with the performance and handling of the helicopter. Source: NTSB Aviation Accident Database Retrieved: 2026-02-12
NTSB Findings
FAA avdata. C = Cause, F = Factor.
- C Personnel issues-Action/decision-Action-Incorrect action performance-Instructor/check pilot - C
- C Aircraft-Aircraft systems-Hydraulic power system-Hydraulic, main system-Simulated malf/failure - C
Verbatim from NTSB's published report. Source file
NTSB_2010_ERA10TA501.txt.
Findings + structured fields enriched from FAA avall.mdb.
Full investigation docket on
data.ntsb.gov ↗.
Search this event elsewhere
External sources are reported, not agency: signal that something happened, not fact about what happened.
- TallyAero Live Wire Aviation press
- NTSB CAROL Agency ↗
- NTSB Docket Agency ↗
- Aviation Safety Network Aviation press ↗
- Kathryn's Report Aviation press ↗
- Aviation Herald Aviation press ↗
- AVweb Aviation press ↗
- Pilots of America Community ↗
- Reddit /r/flying Community ↗
- FlightAware Aviation press ↗
- AOPA accident database Aviation press ↗
- Google News News ↗
- DuckDuckGo News ↗
Related research
Matched on aircraft type or causal vocabulary (loss of control). All research papers
- 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.
- Semantic Scholar 2024 · Article (International Conference on Networking and Services) Risk Assessment of Loss of Control In-Flight Trajectories for Urban Air Mobility Safety
In Urban Air Mobility (UAM), maintaining a minimum separation between aircraft is a safety requirement, which becomes challenging amidst congested air traffic and off-nominal conditions, such as Loss …
- 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.