GAA18CA117

NTSB accident investigation · Hughes Helicopters 369 · Wrightwood, CA · February 1, 2018

Accident · No injuriesData collectionFinal report
Date
February 1, 2018, 09:45 local (17:45 UTC)
Place
Wrightwood, CA
Injuries
3 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N618SGHughes Helicopters 369
Defining event
Landing: Loss of control in flight
Weather
Visual (VMC) · Day
Status
Completed · report August 27, 2018
Report
Approved by Office Director
NTSB office
General Aviation Accidents
Parties
FAA
FAA report
20180201001939A
Case key
96697

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 high altitude, high gross weight landing with insufficient tail rotor thrust resulting in 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.

Tail rotorAircraft › Aircraft propeller/rotor · Capability exceededHughes Helicopters 369E: 1 caseAll aircraft: 23 casesProbable cause
Performance/control parameters: yaw controlAircraft › Aircraft oper/perf/capability · Capability exceededHughes Helicopters 369E: 1 caseAll aircraft: 149 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

The helicopter pilot selected a landing site on a ridge above 8,000 ft mean sea level and initiated an approach. The helicopter descended below effective translational lift airspeed, and the pilot turned the nose of the helicopter to the right. The helicopter developed a rapid right yaw, and he applied full left pedal to arrest the yaw and forward cyclic to fly out of the condition, but the main rotor blades struck the ground. The helicopter came to rest on its left side, and sustained substantial damage to the fuselage, the tailboom and both rotor systems. The pilot reported that the maximum gross weight of the helicopter was 3,000 pounds, and the weight of the helicopter at the time of the accident was 2,700 pounds. According to the recommendation section of the National Transportation Safety Board pilot's aircraft accident report, the pilot reported that the accident could have been prevented if the helicopter wasn't so heavy. Additionally, he noted that he should have selected a better landing area with the landing direction into the wind. Per the Federal Aviation Administration Helicopter Flying Handbook pg. 11-20, "Loss of Tail Rotor Effectiveness [LTE]," when operating at high altitudes and high gross weights, especially while hovering, the tail rotor thrust may not be sufficient to maintain directional control, and LTE can occur. In this case, the hovering ceiling is limited by tail rotor thrust and not necessarily power available. The pilot reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation.

Factual narrative

The helicopter pilot selected a landing site on a ridge above 8,000ft mean sea level, and initiated an approach. The helicopter descended below effective translational lift airspeed, and the pilot turned the nose of the helicopter to the right. The helicopter developed a rapid right yaw, and he applied full left pedal to arrest the yaw, and forward cyclic to fly out of the condition, but the main rotor blades struck the ground. The helicopter came to rest on its left side, and sustained substantial damage to the fuselage, the tailboom and both rotor systems. The pilot reported that the maximum gross weight of the helicopter was 3,000 pounds, and the weight of the helicopter at the time of the accident was 2,700 pounds. According to the Recommendation section of the National Transportation Safety Board Pilot's Aircraft Accident Report, the pilot reported that the accident could have been prevented if the helicopter wasn't so heavy. Additionally, he noted that he should have selected a better landing area with the landing direction into the wind. Per the Federal Aviation Administration Helicopter Flying Handbook pg. 11-20, "Loss of Tail Rotor Effectiveness" LTE at Altitude, when operating at high altitudes and high gross weights, especially while hovering, the tail rotor thrust may not be sufficient to maintain directional control, and LTE can occur. In this case, the hovering ceiling is limited by tail rotor thrust and not necessarily power available. The pilot reported that there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation.

Aircraft

Registration
N618SG
Reported as
Hughes Helicopters 369 (E)
Category
Helicopter
Serial number
0014E
Built
1982
Airframe hours
8,250.8
Engine
Rolls Royce 250-C20B, 420 horsepower, turbo shaft
Damage
Substantial damage
Flight
Part 135
Operator
Western Helicopters, Inc., doing business as Western Helicopters, Inc.
Registered owner
Helicopters Unlimited LLC
Airworthiness certificate
Standard, Normal
Last inspection
Annual · January 2, 2018
Departed
RAL · Riverside, CA
Destination
Wrightwood, CA
Flight plan
Company VFR
Equipment
Handheld GPS, 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
75
Injuries
None
Certificates
Flight instructor, Airline transport, Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane, Helicopter
Medical
Class 2, With waivers/limitations
Last flight review
April 24, 2017
Seat
Left
Restraint
4-point
Flight hours
20,000 total · 7,850 in this make and model · 19,000 as pilot in command · 29 in the last 90 days · 8 in the last 30 days · 3 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
10 statute miles
Temperature
72 °F, dew point 28 °F
Altimeter
30.04 inHg
Observed at
KCCB, 15 nm away

Docket · 2

The files NTSB released with the investigation on June 20, 2018, on NTSB’s docket system: statements, records, photos and specialists’ reports. 4.2 MB 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.