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Atlas / NTSB / CEN21LA153

NTSB CAROL · Event

Event CEN21LA153

2021-02-24 Tulsa, Oklahoma, United States Airport · RVS None 1 aircraft Status: Completed

Registry · N259AM

FAA Aircraft Registry record.

Make / Model

EUROCOPTER EC 130 B4

Year of manufacture

2011 · 10 years old at event

TCDS

H9EU · AIRBUS HELICOPTERS

Engine

TURBOMECA ARRIEL 2B1 (747 hp)

Seats / Engines

6 seats · 1 engine

Last airworthiness date

20220714

ADS-B equipped

Yes — Mode-S A278F9

Registrant of record

AIR METHODS LLC

Source: FAA Aircraft Registry (releasable master file).

Aircraft involved

Probable cause & findings

The pilot’s improper decision to approach the airport and enter a low altitude hover with a gusting quartering tailwind, which resulted in a loss of tail rotor effectiveness during a turn at a low altitude.

Factual narrative

After a west-southwest approach to the airport the pilot entered a low altitude hover near a taxiway intersection where he intended to turn left and join a north/south taxiway before continuing in a hover taxi south toward the ramp. During the counterclockwise turn to join the taxiway, the helicopter’s yaw rate increased as the tail passed through the north-northeast wind. The pilot allowed the helicopter to continue in the turn, despite an increasing left yaw rate, until the nose of the helicopter had realigned with the wind. However, at that point, he was unable to stop the counterclockwise rotation and the helicopter completed at least 2 revolutions before a landing skid struck the ground and the helicopter spun off the taxiway into a grass easement. The pilot and two medical personnel were not injured. The horizontal stabilizer attach fitting on the tail boom was fractured and required replacement. The operator did not report any mechanical malfunctions with the helicopter that would have precluded normal operation. According to a weather report issued about 6 minutes before the accident, the surface wind at the airport was from north-northeast at 8 knots. During the subsequent hour, the wind direction remained unchanged, but the wind speed had increased to 11 knots with 17 knot gusts. A loss of tail rotor effectiveness likely occurred when the helicopter encountered a wind gust during the left turn, which resulted in an increasing counterclockwise yaw rate that the pilot was unable to control. 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).

  • Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Yaw control-Capability exceeded
  • Personnel issues-Action/decision-Info processing/decision-Decision making/judgment-Pilot
  • Personnel issues-Task performance-Use of equip/info-Aircraft control-Pilot
  • Environmental issues-Conditions/weather/phenomena-Wind-Tailwind-Decision related to condition
  • Environmental issues-Conditions/weather/phenomena-Wind-Gusts-Effect on operation
  • Environmental issues-Conditions/weather/phenomena-Wind-Gusts-Ability to respond/compensate

Verbatim from NTSB's published report. Source file NTSB_2021_CEN21LA153.txt. Findings + structured fields enriched from FAA avall.mdb. Full investigation docket on data.ntsb.gov ↗.