# NTSB GAA15CA204: Airbus AS350-B2, N6095U, Tucson, AZ, July 29, 2015 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Data collection · Final report - Date: July 29, 2015, 16:45 local (23:45 UTC) - Place: Tucson, AZ - Coordinates: 32.142223, -111.174446 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=32.1422&lon=-111.1744&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Low altitude operation/event](https://openairdocs.org/ntsb-events/220) - Highest injury: Minor injuries - Injuries: 1 minor, 1 uninjured - Status: Completed, report December 3, 2015 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 91673 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA15CA204 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/91673/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=91673 - Page: https://openairdocs.org/ntsb/GAA15CA204 ## Probable cause The flight instructor's misperception of the helicopter's altitude in relation to the runway surface during a low altitude maneuver, resulting in ground impact. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Perception/orientation/illusion: perception](https://openairdocs.org/ntsb-findings/02022040): Personnel issues › Psychological · Instructor/check pilot (probable cause); cases with it: [Eurocopter AS 350 B2 ECUREUIL, 1 case](https://openairdocs.org/ntsb-findings/02022040/cases.md?model=8680951), [All aircraft, 61 cases](https://openairdocs.org/ntsb-findings/02022040/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Instructor/check pilot (probable cause); cases with it: [Eurocopter AS 350 B2 ECUREUIL, 2 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=8680951), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Eurocopter AS 350 B2 ECUREUIL, 1 case](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=8680951), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-low-alt flying: Low altitude operation/event](https://openairdocs.org/ntsb-events/220) (defining event); cases with it: [Eurocopter AS 350 B2 ECUREUIL, 1 case](https://openairdocs.org/ntsb-events/220/sequence.md?model=8680951), [All aircraft, 780 cases](https://openairdocs.org/ntsb-events/220/sequence.md) - [Maneuvering-low-alt flying: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Eurocopter AS 350 B2 ECUREUIL, 2 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=8680951), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis According to the Pilot/Operator Aircraft Accident Report, the operator reported that, the flight instructor(CFI) was demonstrating the flare portion of an autorotation to the pilot-rated student when the aircraft continued through the power recovery point and impacted the runway. However, during the interview with the CFI and the student, both pilots referred to "flare portion" as the quick stop maneuver, which was the maneuver being performed at the time of the accident. Both pilots stated that they hover taxied to the approach end of the runway, stopped over the runway numbers and established a hover between 65-75 feet above ground level. They reported that they hovered over the runway numbers, facing in the direction of the runway heading, and the CFI described the intricacies of the quick stop maneuver. The CFI specified that the maneuver would terminate to a hover, and initiated the quick stop demonstration by accelerating to the airspeed of 65 knots. The CFI reported that as he talked through the maneuver, he lowered the collective and applied aft cyclic. He stated that as the helicopter began to settle, he misperceived the helicopters altitude in relation to the ground and the helicopter skids impacted the ground hard. Both pilots stated that the CFI responded by increasing collective and the helicopter ascended, started moving aft, and the tail boom separated impacting the left side of the fuselage. The student reported that he and the CFI were both on the controls after the first impact. Both pilots recalled lowering the collective in order to set the helicopter down, the helicopter remained in a level pitch attitude, but yawed left and landed on the skids. The helicopter remained on the ground as the left yaw continued, and the engine was shut down. Both pilots reported that the helicopter spun on the skids, in two complete circles while on the ground, before coming to a stop. The tail boom and main rotor system sustained substantial damage. Both pilots reported that there were no pre-impact mechanical malfunctions or anomalies with any portion of the helicopter that would have prevented normal operations. ## Factual narrative According to the Pilot/Operator Aircraft Accident Report, the operator reported that, the flight instructor(CFI) was demonstrating the flare portion of an autorotation to the pilot-rated student when the aircraft continued through the power recovery point and impacted the runway. However, during the interview with the CFI and the student, both pilots referred to "flare portion" as the quick stop maneuver, which was the maneuver being performed at the time of the accident. Both pilots stated that they hover taxied to the approach end of the runway, stopped over the runway numbers and established a hover between 65-75 feet above ground level. They reported that they hovered over the runway numbers, facing in the direction of the runway heading, and the CFI described the intricacies of the quick stop maneuver. The CFI specified that the maneuver would terminate to a hover, and initiated the quick stop demonstration by accelerating to the airspeed of 65 knots. The CFI reported that as he talked through the maneuver, he lowered the collective and applied aft cyclic. He stated that as the helicopter began to settle, he misperceived the helicopters altitude in relation to the ground and the helicopter skids impacted the ground hard. Both pilots stated that the CFI responded by increasing collective and the helicopter ascended, started moving aft, and the tail boom separated impacting the left side of the fuselage. The student reported that he and the CFI were both on the controls after the first impact. Both pilots recalled lowering the collective in order to set the helicopter down, the helicopter remained in a level pitch attitude, but yawed left and landed on the skids. The helicopter remained on the ground as the left yaw continued, and the engine was shut down. Both pilots reported that the helicopter spun on the skids, in two complete circles while on the ground, before coming to a stop. The tail boom and main rotor system sustained substantial damage. Both pilots reported that there were no pre-impact mechanical malfunctions or anomalies with any portion of the helicopter that would have prevented normal operations. ## Aircraft - Registration: [N6095U](https://openairdocs.org/deregistered/N6095U-2022-01-08), registration cancelled 2022-01-08, S/N 2699, built 1993 (OpenAirDocs) - Reported make and model: AIRBUS AS350-B2 - Registry model: [Eurocopter AS 350 B2 ECUREUIL](https://openairdocs.org/model/eurocopter-as-350-b2-ecureuil) (registry code 8680951) (OpenAirDocs) - Registry engine: [Turbomeca ARRIEL-1SER](https://openairdocs.org/engine/turbomeca-arriel-1ser) (registry code 60030, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 2699 - Year built: 1993 - Airframe hours: 12629.3 - Engines: Turbomeca Arriel/1D1 732 horsepower turbo shaft - Damage: Substantial damage - Flight: Public aircraft - federal, Public use - Operator: US Department Of Homeland Security - Registered owner: US Department Of Homeland Security - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, July 6, 2015, 80 hours before - Departed: DMA, TUCSON, AZ - Destination: RYN, Tucson, AZ - Flight plan: Company VFR - Airport: RYN, Ryan Field, runway 24R, 4,900 × 75 ft, asphalt - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 48; injuries: minor; flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: helicopter, airplane; medical: class 2, with waivers/limitations; last flight review July 15, 2015; seat: left; restraint: 4-point; toxicology performed; flight hours: 6,399 total, 2,178 in this make and model, 5,284 as pilot in command, 62 in the last 90 days, 29 in the last 30 days, 4 in the last 24 hours - Pilot; age 46; injuries: none; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane, helicopter; medical: class 2, without waivers/limitations; last flight review June 3, 2015; seat: right; restraint: 4-point; toxicology performed; flight hours: 2,500 total, 200 in this make and model, 1,160 as pilot in command, 31 in the last 90 days, 1 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 270° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 95 °F, dew point 61 °F - Altimeter: 29.98 inHg - Observed at: RYN ## 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 20150729023209A](https://openairdocs.org/incident/20150729023209A), Jul 29, 2015: Eurocopter AS 350 B2 ECUREUIL, Tucson, AZ, Substantial damage. Instructor was demonstrating auto-rotation technique to pilot over rwy 24R at ryn. During the procedure the instructor was not able to arrest descent and… ## Docket (3 files) The files NTSB released with the investigation on November 17, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=91673. 2.5 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40434017&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Accident Site Diagram (item 2, .PDF, 374 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40434018&FileExtension=.PDF&FileName=Accident%20Site%20Diagram-Master.PDF - Photo (item 3, .PDF, 219 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40434019&FileExtension=.PDF&FileName=Photo-Master.PDF 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.