GAA17CA495

NTSB accident investigation · Bell 206 · Minden, NV · August 20, 2017

Accident · No injuriesData collectionFinal report
Date
August 20, 2017, 12:30 local (19:30 UTC)
Place
Minden, NV
Injuries
5 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N6259CBell 206
Defining event
Landing: Loss of tail rotor effectiveness
Weather
Visual (VMC) · Day
Status
Completed · report November 27, 2017
Report
Approved by Office Director
NTSB office
General Aviation Accidents
Parties
FAA
FAA report
20170820010439A
Case key
95841

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 failure to maintain helicopter control during landing due to a loss of tail rotor effectiveness.

Findings · 3

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.

Use of equip/info: aircraft controlPersonnel issues › Task performance · PilotBell 206B: 45 casesAll aircraft: 9,295 casesProbable cause
Performance/control parameters: prop/rotor parametersAircraft › Aircraft oper/perf/capability · Not attained/maintainedBell 206B: 11 casesAll aircraft: 182 casesProbable cause
Object/animal/substance: fence/fence postEnvironmental issues › Physical environment · Contributed to outcomeBell 206B: 1 caseAll aircraft: 313 cases

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

The pilot of the helicopter reported that, during landing, the helicopter "encountered LTE [loss of tail rotor effectiveness]." He added that he maneuvered the helicopter to an open field adjacent to the intended helipad and that the tail rotor impacted a barbed wire fence. The helicopter sustained substantial damage to the empennage. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. The Federal Aviation Administration's Helicopter Flying Handbook, FAA-H-8083-21A, contained a section titled "Loss of Tail Rotor Effectiveness (LTE)," which stated: Loss of tail rotor effectiveness (LTE) or an unanticipated yaw is defined as an uncommanded, rapid yaw towards the advancing blade which does not subside of its own accord. It can result in the loss of the aircraft if left unchecked. It is very important for pilots to understand that LTE is caused by an aerodynamic interaction between the main rotor and tail rotor and not caused from a mechanical failure. Some helicopter types are more likely to encounter LTE due to the normal certification thrust produced by having a tail rotor that, although meeting certification standards, is not always able to produce the additional thrust demanded by the pilot.

Factual narrative

The pilot of the helicopter reported that, during landing, the helicopter "encountered LTE [loss of tail rotor effectiveness]". He added that he maneuvered the helicopter to an open field adjacent to the intended helipad and the tail rotor impacted a barbed wire fence. The helicopter sustained substantial damage to the empennage. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. Federal Aviation Administration's Helicopter Flying Handbook, FAA-H-8083-21A, contains a section titled "Loss of Tail Rotor Effectiveness (LTE)" which states: Loss of tail rotor effectiveness (LTE) or an unanticipated yaw is defined as an uncommanded, rapid yaw towards the advancing blade which does not subside of its own accord. It can result in the loss of the aircraft if left unchecked. It is very important for pilots to understand that LTE is caused by an aerodynamic interaction between the main rotor and tail rotor and not caused from a mechanical failure. Some helicopter types are more likely to encounter LTE due to the normal certification thrust produced by having a tail rotor that, although meeting certification standards, is not always able to produce the additional thrust demanded by the pilot.

Aircraft

Registration
N6259C
Reported as
Bell 206 (B)
Category
Helicopter
Serial number
703
Built
1971
Airframe hours
22,237.4
Engine
Rolls Royce 250-C20B, 320 horsepower, turbo shaft
Damage
Substantial damage
Flight
Personal · Part 91
Operator
Helicopter Parts International Inc
Registered owner
Helicopter Parts International Inc
Airworthiness certificate
Standard, Normal
Last inspection
Annual · May 11, 2017
Destination
MEV · Minden, NV
Airport
MEV · Minden-Tahoe
Equipment
None

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
63
Injuries
None
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, Without waivers/limitations
Last flight review
May 13, 2017
Seat
Right
Restraint
4-point
Flight hours
664 total · 562 in this make and model

Weather

Conditions
Visual (VMC) · Day
Wind
Variable at 3 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
77 °F, dew point 45 °F
Altimeter
30.17 inHg
Observed at
KMEV

Docket · 2

The files NTSB released with the investigation on October 31, 2017, on NTSB’s docket system: statements, records, photos and specialists’ reports. 975 KB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.