GAA17CA562

NTSB accident investigation · Eurocopter AS 350 · Fullerton, CA · September 27, 2017

Accident · Minor injuriesData collectionFinal report
Date
September 27, 2017, 10:00 local (17:00 UTC)
Place
Fullerton, CA
Injuries
2 minor
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N515ETEurocopter AS 350
Defining event
Maneuvering-low-alt flying: Loss of control in flight
Weather
Visual (VMC) · Day
Status
Completed · report June 14, 2018
Report
Approved by Office Director
NTSB office
General Aviation Accidents
Parties
FAA
FAA report
20170927024719A
Case key
96108

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 under evaluation’s failure to maintain adequate airspeed during a simulated hydraulic failure, which resulted in a loss of helicopter control. Contributing to the accident was the check pilot’s delayed remedial action.

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 · PilotEurocopter AS 350 B2: 13 casesAll aircraft: 9,295 casesProbable cause
Performance/control parameters: airspeedAircraft › Aircraft oper/perf/capability · Not attained/maintainedEurocopter AS 350 B2: 2 casesAll aircraft: 1,681 casesProbable cause
Action: delayed actionPersonnel issues › Action/decision · Instructor/check pilotEurocopter AS 350 B2: 4 casesAll aircraft: 894 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 check pilot reported that he was administering an annual standardization check ride in the public helicopter. The last maneuver evaluated was a hydraulic failure that would terminate by accomplishing a simulated run-on landing. The maneuver was initiated when the evaluated pilot established an out-of-ground-effect (OGE) hover on the downwind leg of the pattern. The check pilot engaged the hydraulic test button on the center console to "simulate a hydraulic failure." The evaluated pilot lowered the nose and established forward airspeed to maintain controllability. He maintained stabilized forward flight on the downwind leg, and the check pilot disengaged the hydraulic test button. The check pilot moved the hydraulic cutoff switch to the "off" position, and the hydraulic system was disengaged. The evaluated pilot remained on the controls and established a shallow approach until about 3 ft above the runway. Over the runway, the evaluated pilot allowed the helicopter's airspeed to decrease, and the check pilot stated, "Keep the speed up." The evaluated pilot responded by lowering the nose; however, an uncontrollable rapid left yaw ensued. The check pilot took control of the helicopter and attempted to keep the helicopter over the runway, but the nose pitched down, and the main rotor blades struck the ground. The check pilot decreased the fuel control, and the helicopter settled upright on the runway. The helicopter sustained substantial damage to the windscreen above the cabin, the tailboom, and tail rotor drive system. The METAR at the accident airport reported that, at the time of the accident, the wind from 250° at 3 knots, the skies were clear, and the temperature was 72°F. According to the Operator's Flight Manual: In case of loss of hydraulic pressure, the recommended safety speed range is from 40 to 60 kt. CAUTION: DO NOT ATTEMPT TO CARRY OUT HOVER FLIGHT OR ANY LOW SPEED MANEUVER WITHOUT HYDRAULIC PRESSURE ASSISTANCE. THE INTENSITY AND DIRECTION OF THE CONTROL FEEDBACK FORCES WILL CHANGE RAPIDLY. THIS WILL RESULT IN EXCESSIVE PILOT WORKLOAD, POOR AIRCRAFT CONTROL, AND POSSIBLE LOSS OF CONTROL. Postaccident examination revealed no mechanical malfunctions or anomalies that would have precluded normal operation.

Factual narrative

The check pilot reported that he was administering an annual standardization check ride in the public use helicopter. The last maneuver evaluated was a hydraulic failure that would terminate by accomplishing a simulated run-on landing. The maneuver was initiated when the check/evaluated pilot established an out of ground effect (OGE) hover on the downwind leg of the pattern. The check-pilot engaged the hydraulic test button on the center console to "simulate a hydraulic failure." The evaluated pilot lowered the nose and established forward airspeed to maintain aircraft controllability. He maintained stabilized forward flight on the downwind leg, and the check-pilot disengage the hydraulic test button. The check pilot moved the hydraulic cut off switch to the off position, and the hydraulic system was disengaged. The evaluated pilot remained on the controls and established a shallow approach until about 3ft above the runway. Over the runway, the evaluated pilot allowed the helicopter's airspeed to decrease, and the check-pilot stated, "Keep the speed up." The evaluated pilot responded by lowering the nose, however, an uncontrollable rapid left yaw ensued. The check-pilot took control of the helicopter and attempted to keep the helicopter over the runway, but the nose pitched down, and the main rotor blades struck the ground. The check pilot decreased the fuel control and the helicopter settled upright on the runway. The helicopter sustained substantial damage to the windscreen above the cabin, the tailboom and tail rotor drive system. The METAR at the accident airport during the time of the accident reported that the wind from 250° at 3kts, the skies were clear, and the temperature was 72°F. According to the Operator's Flight Manual: In case of loss of hydraulic pressure, the recommended safety speed range is from 40 to 60 kt. CAUTION: DO NOT ATTEMPT TO CARRY OUT HOVER FLIGHT OR ANY LOW SPEED MANEUVER WITHOUT HYDRAULIC PRESSURE ASSISTANCE. THE INTENSITY AND DIRECTION OF THE CONTROL FEEDBACK FORCES WILL CHANGE RAPIDLY. THIS WILL RESULT IN EXCESSIVE PILOT WORKLOAD, POOR AIRCRAFT CONTROL, AND POSSIBLE LOSS OF CONTROL. There were no mechanical malfunctions or anomalies that were identified as a result of this investigation.

Aircraft

Registration
N515ET
Reported as
Eurocopter AS 350 (B2)
Category
Helicopter
Serial number
3425
Built
2001
Airframe hours
4,636
Engine
Turbomeca Arriel 1D1, 9,783 horsepower, turbo shaft
Damage
Substantial damage
Flight
Instructional · Public use
Operator
Chaparral Air Group
Registered owner
Chaparral Air Group
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · September 11, 2017
Departed
LGB · Long Beach, CA
Destination
FUL · Fullerton, CA
Airport
FUL · Fullerton Muni, runway 24, 3,121 × 75 ft, asphalt
Equipment
Electronic multifunction display, 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 · 2

As NTSB recorded them. NTSB leaves out names.

Role
Check pilot
Age
56
Injuries
Minor
Certificates
Flight instructor, Commercial, Airline transport
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane, Helicopter
Medical
Class 1, With waivers/limitations
Last flight review
December 5, 2016
Seat
Left
Flight hours
8,259 total · 918 in this make and model · 6,705 as pilot in command · 128 in the last 90 days · 27 in the last 30 days · 5 in the last 24 hours
Role
Pilot
Age
51
Injuries
Minor
Certificate
Commercial
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane, Helicopter
Medical
Class 1, With waivers/limitations
Last flight review
June 15, 2017
Seat
Right
Flight hours
3,915 total · 158 in this make and model · 3,663 as pilot in command · 55 in the last 90 days · 31 in the last 30 days · 2 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
250° at 3 knots
Visibility
6 statute miles
Lowest ceiling
None
Temperature
72 °F, dew point 63 °F
Altimeter
29.88 inHg
Observed at
KFUL

Docket · 3

The files NTSB released with the investigation on April 25, 2018, on NTSB’s docket system: statements, records, photos and specialists’ reports. 4.7 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.