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GAA16CA296

2016-06-07 · Cahokia/St. Louis, Illinois, United States · None · 1 aircraft · Status: Completed

Airport CPS

Current FAA registration · N931SH

Make / Model
ROBINSON HELICOPTER R22 BETA
Year of manufacture
2005 · 11 years old at event
Engine
LYCOMING O-360 SERIES (180 hp)
Seats / Engines
2 seats · 1 engine
Last airworthiness date
20050822
ADS-B equipped
Yes — Mode-S ACEAF8

Source: FAA Aircraft Registry (releasable master file).

Aircraft involved

Probable cause & findings

The flight instructor's delayed remedial action and his failure to remain vigilant as the helicopter entered the weathercock stability region, in gusting wind conditions, resulting in loss of tail rotor effectiveness and ground impact.

Factual narrative

According to the flight instructor, he was instructing his student in hovering flight operations. He reported that he instructed the student to execute a right pedal turn at a three foot hover. The instructor recalled that the student complied and during the turn, as the tail came into the wind, the helicopter started to weathervane, and the turn rate increased rapidly and did not subside until the helicopter impacted the ground. The helicopter sustained substantial damage to the fuselage and both rotor systems. The instructor reported that there were no mechanical anomalies or malfunctions with any portion of the helicopter that would prevent normal flight operations. The instructor reported that the wind velocity at the time of the accident was 11 knots gusting to 16 knots. Weathercock stability is defined as a region of loss of tail rotor effectiveness (120 degree - 240 degree tailwind) that will weathervane the helicopter, and if not prevented will result in a loss of helicopter control about the horizontal axis. According to the Helicopter Flying Handbook (FAA 8083-21A): Pilots who put themselves in situations where the combinations above occur should know that they are likely to encounter LTE. The key is to not put the helicopter in a compromising condition but if it does happen being educated enough to recognize the onset of LTE and be prepared to quickly react to it before the helicopter cannot be controlled. According to the flight instructor, he was instructing his student in hovering flight operations. He reported that he instructed the student to execute a right pedal turn at a three foot hover. The instructor recalled that the student complied and during the turn, as the tail came into the wind, the helicopter started to weathervane, and the turn rate increased rapidly and did not subside until the helicopter impacted the ground. The helicopter sustained substantial damage to the fuselage and both rotor systems. The instructor reported that there were no mechanical anomalies or malfunctions with any portion of the helicopter that would prevent normal flight operations. The instructor reported that the wind velocity at the time of the accident was 11 knots gusting to 16 knots. Weathercock stability is defined as a region of loss of tail rotor effectiveness (120 degree - 240 degree tailwind) that will weathervane the helicopter, and if not prevented will result in a loss of helicopter control about the horizontal axis. According to the Helicopter Flying Handbook (FAA 8083-21A):   Pilots who put themselves in situations where the combinations above occur should know that they are likely to encounter LTE. The key is to not put the helicopter in a compromising condition but if it does happen being educated enough to recognize the onset of LTE and be prepared to quickly react to it before the helicopter cannot be controlled. Source: NTSB Aviation Accident Database Retrieved: 2026-02-12

NTSB Findings

FAA avdata. C = Cause, F = Factor.

  • C Personnel issues-Action/decision-Action-Delayed action-Instructor/check pilot - C
  • C Personnel issues-Psychological-Attention/monitoring-Task monitoring/vigilance-Instructor/check pilot - C
  • C Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Prop/rotor parameters-Not attained/maintained - C
  • C Environmental issues-Conditions/weather/phenomena-Wind-Gusts-Effect on operation - C
  • — Environmental issues-Physical environment-Terrain-(general)-Contributed to outcome

Verbatim from NTSB's published report. Source file NTSB_2016_GAA16CA296.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.