# NTSB LAX04CA097: Eurocopter AS350 B3, N970AE, Mesa, AZ, January 20, 2004 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: January 20, 2004, 09:50 local (16:50 UTC) - Place: Mesa, AZ - Coordinates: 33.460834, -111.728332 - Nearby events: https://openairdocs.org/map.md?lat=33.4608&lon=-111.7283&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report March 30, 2004 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 58644 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX04CA097 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/58644/pdf - Page: https://openairdocs.org/ntsb/LAX04CA097 ## 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 In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Hard landing, landing - flare/touchdown - autorotation - initiated, dual student - flare - excessive, dual student (cause) - collective - improper use of, dual student (cause) - remedial action - delayed, pilot in command(cfi) (cause) - rotor rpm - not maintained, pilot in command(cfi) (cause) - supervision - inadequate, pilot in command(cfi) (cause) - Roll over, landing - flare/touchdown - terrain condition - soft (contributing factor) ## 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](https://openairdocs.org/aircraft/N970AE), registered now, S/N 3235, built 1999 (OpenAirDocs) - Reported make and model: Eurocopter AS350 B3 - Registry model: [Eurocopter AS 350 B3](https://openairdocs.org/model/eurocopter-as-350-b3) (registry code 8680954) (OpenAirDocs) - Registry engine: [Turbomeca ARRIEL series](https://openairdocs.org/engine/turbomeca-arriel-series) (registry code 60031, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 3235 - Engines: 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 ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 48; 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 - Co-pilot; age 34; 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 (OpenAirDocs). - [Accident 20040120000269A](https://openairdocs.org/incident/20040120000269A), Jan 20, 2004: Snias AS350B3, Mesa, AZ, Substantial damage. (-23) While conducting a training flight in the area of ffz, the pilot entered a practice autorotation @ 1900' (MSL)/80 KIAS. The autorotation was set up… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.