LAX04CA097

NTSB accident investigation · Eurocopter AS350 B3 · Mesa, AZ · January 20, 2004

Accident · No injuriesData collectionFinal report
Date
January 20, 2004, 09:50 local (16:50 UTC)
Place
Mesa, AZ
Injuries
3 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N970AEEurocopter AS350 B3
Weather
Visual (VMC) · Day
Status
Completed · report March 30, 2004
Report
Approved by Office Director
Parties
Federal Aviation Administration
FAA report
20040120000269A
Case key
58644

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 excessive flare and mistimed collective application during a practice autorotation, which resulted in a loss of main rotor rpm and a subsequent hard landing. Also causal, was the flight instructor's delayed remedial action and inadequate supervision of the flight. The soft terrain was a factor.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Hard landingLanding - flare/touchdown
Autorotation - initiatedDual student
Flare - excessiveDual studentCause
Collective - improper use ofDual studentCause
Remedial action - delayedPilot in command(cfi)Cause
Rotor rpm - not maintainedPilot in command(cfi)Cause
Supervision - inadequatePilot in command(cfi)Cause
Roll overLanding - flare/touchdown
Terrain condition - softFactor

Analysis

The helicopter landed hard and rolled over during a practice autorotation. The purpose of the flight was for the flight instructor to give the flying pilot the recurrent flight checks required by 14 CFR Part 135. They entered a landing pattern parallel to 22R. At 500 feet above ground level (agl) and 80 knots indicated airspeed (IAS), the flight instructor initiated an engine failure. The pilot responded appropriately and entered an autorotation with 60 knots IAS and 398 rpm rotor speed (Nr). At 60 feet agl, the pilot began the flare; however, it was more aggressive than necessary for the conditions. The pilot then lowered the nose after being advised by the flight instructor to do so. At 30 feet agl, the pilot began to increase the collective; the Nr dropped to 380. The flight instructor announced, "I am on the controls with you," and then, "I have the controls." The flight instructor leveled the helicopter and reduced the collective. About 5 feet agl, the flight instructor initiated the final collective application. As the Nr decreased, the tail rotor lost effectiveness; the helicopter yawed to the left with full right anti-torque pedal applied. The helicopter touched down and the nose was approximately 15 degrees to the left of the direction of travel. The right skid touched down and the helicopter drifted to the right. The helicopter then rolled to the right despite corrective inputs by the flight instructor. The front portion of the right skid dug into the soft turf and pivoted the helicopter forward and the main rotor blades contacted the ground. No mechanical malfunctions were reported.

Factual narrative

On January 20, 2004, about 0950 mountain standard time, an Eurocopter AS 350 B3, N970AE, landed hard during a practice autorotation at the Falcon Field (FFZ) airport, Mesa, Arizona. The helicopter came to rest on its right side. Petroleum Helicopters, Inc., was operating the helicopter under the provisions of 14 CFR Part 91. The airline transport certificated flight instructor, the commercial pilot undergoing instruction (PUI), and one passenger, were not injured. The airplane sustained substantial damage. The local instructional flight departed Phoenix Sky Harbor International Airport (PHX), Phoenix, Arizona, at 0910, en route to Falcon Field. Visual meteorological conditions prevailed, and no flight plan had been filed.

In a written statement, the flight instructor reported that the purpose of the flight was to give the PUI the recurrent flight checks required by 14 CFR Part 135. They entered a landing pattern parallel to 22R. At 500 feet above ground level (agl) and 80 knots indicated airspeed (IAS), the flight instructor initiated an engine failure. The PUI responded appropriately and entered an autorotation with 60 knots IAS and 398 rpm rotor speed (Nr). At 60 feet agl, the PUI began the flare; however, it was more aggressive than necessary for the conditions. The PUI then lowered the nose after being advised by the flight instructor to do so. At 30 feet agl, the PUI began to increase the collective; the Nr dropped to 380. The flight instructor announced, "I am on the controls with you," and then, "I have the controls." The flight instructor leveled the helicopter and reduced the collective. About 5 feet agl, the flight instructor initiated the final collective application. As the Nr decreased, the tail rotor lost effectiveness; the helicopter yawed to the left with full right anti-torque pedal applied.

The helicopter touched down and the nose was approximately 15 degrees to the left of the direction of travel. The right skid touched down and the helicopter drifted to the right. The helicopter then rolled to the right despite corrective inputs by the flight instructor. He immediately turned the start switch to the "OFF" position and reached for the emergency fuel shutoff handle. The front portion of the right skid dug into the soft turf and pivoted the helicopter forward and the main rotor blades contacted the ground. No mechanical malfunctions were noted with the helicopter.

Aircraft

Registration
N970AE
Reported as
Eurocopter AS350 B3
Category
Helicopter
Serial number
3235
Engine
Turbomeca Arriel 2B, reciprocating
Damage
Substantial damage
Flight
Instructional · Part 91
Operator
Petroleum Helicopters
Registered owner
Petroleum Helicopters
Airworthiness certificate
Standard, Normal
Departed
PHX · Phoenix, AZ
Destination
FFZ · Falcon Field, AZ
Airport
FFZ · Falcon Field

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
Pilot
Age
48
Certificates
Flight instructor, Commercial
Airplane ratings
Single-engine land
Instrument ratings
Helicopter, Airplane
Medical
Class 2
Flight hours
4,053 total · 142 in this make and model · 4 in the last 90 days · 3 in the last 30 days
Role
Co-pilot
Age
34
Certificates
Flight instructor, Airline transport
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Helicopter, Airplane
Medical
Class 2
Flight hours
3,400 total · 300 in this make and model · 80 in the last 90 days · 1 in the last 30 days

Weather

Conditions
Visual (VMC) · Day

FAA reports on this event · 1

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