CEN21LA153

NTSB accident investigation · Eurocopter EC130 · Tulsa, OK · February 25, 2021

Accident · No injuriesClass 4 · LimitedFinal report
Date
February 24, 2021, 22:59 local (Feb 25, 2021, 04:59 UTC)
Place
Tulsa, OK · airport taxiway
Injuries
3 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N259AMEurocopter EC130
Defining event
Landing: Loss of tail rotor effectiveness
Weather
Visual (VMC) · Night
Status
Completed
Report
Approved by Office Director
Investigation class
Class 4 - Basic report with no Prelim publish
NTSB office
Central Region
Parties
Federal Aviation Administration, Oklahoma City FSDO, Air Methods
Case key
102733

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

On this page

Probable cause

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.

Findings · 6

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Performance/control parameters: yaw controlAircraft › Aircraft oper/perf/capability · Capability exceededEurocopter EC 130 B4: 2 casesAll aircraft: 149 casesProbable cause
Use of equip/info: aircraft controlPersonnel issues › Task performance · PilotEurocopter EC 130 B4: 6 casesAll aircraft: 9,295 casesProbable cause
Wind: tailwindEnvironmental issues › Conditions/weather/phenomena · Decision related to conditionEurocopter EC 130 B4: 3 casesAll aircraft: 594 casesProbable cause
Wind: gustsEnvironmental issues › Conditions/weather/phenomena · Effect on operationEurocopter EC 130 B4: 1 caseAll aircraft: 1,199 casesProbable cause
Wind: gustsEnvironmental issues › Conditions/weather/phenomena · Ability to respond/compensateEurocopter EC 130 B4: 1 caseAll aircraft: 1,199 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

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.

Aircraft

Registration
N259AM
Reported as
Eurocopter EC130 (B4)
Category
Helicopter
Serial number
7050
Built
2011
Airframe hours
4,050.4
Engine
Turbomeca Arriel 2B1, 747 horsepower, turbo shaft
Damage
Substantial damage
Flight
Part 135
Operator
Air Methods Corporation
Registered owner
Air Methods Corporation
Airworthiness certificate
Standard, Normal
Last inspection
AAIP · February 24, 2021
Departed
4OK3 · Tulsa, OK
Destination
Same as departure
Flight plan
VFR
Airport
RVS · Richard Lloyd Jones, Jr.
Equipment
ADS-B, Satellite tracking device

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
56
Injuries
None
Certificate
Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane, Helicopter
Medical
Class 2, Without waivers/limitations
Last flight review
April 5, 2020
Seat
Left
Flight hours
4,587 total · 451 in this make and model · 18 in the last 90 days · 9 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Night
Wind
20° at 8 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
43 °F, dew point 30 °F
Altimeter
30.29 inHg
Observed at
RVS
METAR
METAR KRVS 250453Z AUTO 02008KT 10SM CLR 06/M01 A3029 RMK AO2 SLP263 T00611006=

Docket · 9

The files NTSB released with the investigation on August 26, 2021, on NTSB’s docket system: statements, records, photos and specialists’ reports. 7.6 MB in all.