GAA18CA571

NTSB accident investigation · Eurocopter AS350 · Ruidoso, NM · September 29, 2018

Accident · No injuriesData collectionFinal report
Date
September 29, 2018, 15:10 local (21:10 UTC)
Place
Ruidoso, NM
Injuries
3 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N894NAEurocopter AS350
Defining event
Landing-flare/touchdown: Hard landing
Weather
Visual (VMC) · Day
Status
Completed · report March 20, 2020
Report
Approved by Office Director
NTSB office
General Aviation Accidents
Parties
FAA
FAA report
20180929016489A
Case key
98387

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

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Probable cause

The pilot's failure to maintain the proper descent rate during landing. Contributing to the accident were the pilot’s failure to conduct preflight performance calculations, which resulted in his operating the helicopter in high-density altitude conditions, and his lack of experience in high-altitude, mountainous flying.

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: descent rateAircraft › Aircraft oper/perf/capability · Not attained/maintainedEurocopter AS 350 B2: 2 casesAll aircraft: 242 casesProbable cause
Use of equip/info: aircraft controlPersonnel issues › Task performance · PilotEurocopter AS 350 B2: 13 casesAll aircraft: 9,295 casesProbable cause
Experience/qualifications: total experiencePersonnel issues › Experience/knowledge · PilotEurocopter AS 350 B2: 1 caseAll aircraft: 126 casesProbable cause
Temp/humidity/pressure: high density altitudeEnvironmental issues › Conditions/weather/phenomena · Effect on operationEurocopter AS 350 B2: 2 casesAll aircraft: 278 casesProbable cause
Training: cRM/MRM trainingOrganizational issues › Support/oversight/monitoring · OperatorEurocopter AS 350 B2: 1 caseAll aircraft: 2 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 helicopter pilot was conducting an emergency medical services flight. He reported that, while en route to a ski resort to pick up a patient, he decided to conduct an eastbound reconnaissance over the landing site to scan for obstacles. He saw two cables in front and below the helicopter 's flightpath and initiated a go-around. He added power to clear the cables, and once the tail cleared the cables, he lowered the collective due to a slight drop in the main rotor speed. As he continued the go-around, he initiated a 180º left turn to attempt an approach to the landing site. During the westward approach and while the helicopter was about 20 ft above ground level, he raised the collective to reduce the descent rate, and the main rotor speed subsequently decayed. He felt that, due to the "faster than normal" descent rate, he would not be able to cushion the landing. Before touchdown, a medical crewmember spotted an elevated steel barrier cable below the helicopter, and the pilot made a 90º left turn to avoid a tail rotor strike. The helicopter subsequently touched down hard, bounced, rotated about 180º counterclockwise over the barrier cable, slid down an embankment, and came to rest upright. The helicopter sustained substantial damage to the fuselage and vertical stabilizer. The director of operations reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. The pilot reported that, during his preflight preparation, he did not calculate the hover-in-ground-effect value, the hover out-of-ground-effect value, or the density altitude for the designated landing site. He added that the accident flight was his second flight in a high-altitude, mountainous environment and that most of his flight hours were accumulated at sea level. He was not aware that the ski resort provided an approach, landing, and takeoff procedure. He added that he should have completed the go-around and circled back around to land. A Federal Aviation Administration inspector reported that, at the time of the accident, the density altitude for the landing site at 9,793 ft was over 12,000 ft.

Factual narrative

The helicopter pilot reported that while enroute to the ski resort to pick up a patient, he decided to conduct an eastbound reconnaissance over the landing site and, after he saw the ground personnel, while scanning for obstacles, he spotted two cables in front and below the aircraft's flight path and initiated a go-around. He added power to clear the cables, and once the tail cleared the cables, he lowered the collective due to a slight droop in the main rotor speed. As he continued with the go-around, he initiated a 180º left turn to attempt an approach into the landing site. During the westward approach, about 20 feet above the ground, the main rotor speed decayed when he raised the collective to reduce his descent rate. He felt that due to his "faster than normal" decent rate, he would not be able to cushion the landing. Prior to touchdown, a medical crew member spotted an elevated steel barrier cable below and the pilot applied another 90º turn to the left to avoid a tail rotor strike. The helicopter touched down hard, bounced, rotated about 180º counterclockwise over the barrier cable, slid down an embankment, and came to rest upright. The helicopter sustained substantial damage to the fuselage and vertical stabilizer. The Director of Operations reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. The pilot further reported that during his preflight preparation, he did not calculate the hover in ground effect value (HIGE), the hover out of ground effect value (HOGE), or the density altitude for the designated landing site. He added that the accident flight was his second flight in a high altitude, mountainous environment and that most of his flight hours were accumulated at sea level in Texas. He was also not aware that there was an approach, landing and takeoff procedure provided by the ski resort. The director of operations added that the company was not aware that there were dedicated procedures for helicopter medical evacuation. The crew members added that the crew resource management skills and procedures were lacking, prior to and during the accident. They reported that there was no destination or helicopter performance briefing included with the helicopter preflight. The pilot added that he should have completed the go-around and circled back around to land. The Federal Aviation Administration inspector reported, during the time of the accident, the density altitude for the landing site at 9,793 ft was over 12,000 ft. The automated weather observation station located on an airport about 14 NM away, reported that, about the time of the accident, the wind was from 220° at 9 knots, gusting 17 knots. The pilot reported the wind was variable, about 5 knots. The helicopter was landing to the west.

Aircraft

Registration
N894NA
Reported as
Eurocopter AS350 (B2)
Category
Helicopter
Serial number
2904
Built
1996
Airframe hours
8,199.4
Engine
Turbomeca Arriel 1D1, turbo shaft
Damage
Substantial damage
Flight
Part 135
Operator
Trans Aero Limited, doing business as Trans Aero MedEvac
Registered owner
Roberts Aircraft Co
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · April 9, 2018
Departed
ATS · Artesia, NM
Destination
El Paso, TX
Flight plan
Unknown
Equipment
Electronic flight bag or handheld device, Video recording device, 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
53
Injuries
Minor
Certificates
Commercial, Flight instructor
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane, Helicopter
Medical
Class 2, With waivers/limitations
Last flight review
April 12, 2018
Seat
Right
Restraint
4-point
Flight hours
16,818 total · 3,526 in this make and model · 16,818 as pilot in command · 56 in the last 90 days · 26 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
220° at 9 knots, gusting 17
Temperature
77 °F, dew point 41 °F
Altimeter
30.27 inHg
Observed at
KSRR, 14 nm away

Docket · 9

The files NTSB released with the investigation on December 10, 2019, 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.