# NTSB GAA16CA179: Bell 206, N73AW, Supai, AZ, April 6, 2016 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Data collection · Final report - Date: April 6, 2016, 16:10 local (22:10 UTC) - Place: Supai, AZ - Coordinates: 36.146389, -112.758613 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=36.1464&lon=-112.7586&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: External load event (Rotorcraft)](https://openairdocs.org/ntsb-events/480) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report June 1, 2016 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 92971 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA16CA179 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/92971/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=92971 - Page: https://openairdocs.org/ntsb/GAA16CA179 ## Probable cause The pilot's decision to fly a normal approach and forgetting that the long line remained attached to the helicopter, which resulted in the line snagging on a ridgeline, a loss of lateral control, and a rollover. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Action: forgotten action/omission](https://openairdocs.org/ntsb-findings/02041035): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Bell 206-L4, 1 case](https://openairdocs.org/ntsb-findings/02041035/cases.md?model=1182110), [All aircraft, 442 cases](https://openairdocs.org/ntsb-findings/02041035/cases.md) - [Action: incorrect action performance](https://openairdocs.org/ntsb-findings/02041015): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Bell 206-L4, 2 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md?model=1182110), [All aircraft, 1,387 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md) - [Performance/control parameters: lateral/bank control](https://openairdocs.org/ntsb-findings/01062023): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [Bell 206-L4, 3 cases](https://openairdocs.org/ntsb-findings/01062023/cases.md?model=1182110), [All aircraft, 391 cases](https://openairdocs.org/ntsb-findings/01062023/cases.md) - [Equipment/furnishings: agricultural/external load sys](https://openairdocs.org/ntsb-findings/01022551): Aircraft › Aircraft systems · Not inspected (probable cause); cases with it: [Bell 206-L4, 1 case](https://openairdocs.org/ntsb-findings/01022551/cases.md?model=1182110), [All aircraft, 14 cases](https://openairdocs.org/ntsb-findings/01022551/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing: External load event (Rotorcraft)](https://openairdocs.org/ntsb-events/480) (defining event); cases with it: [Bell 206-L4, 1 case](https://openairdocs.org/ntsb-events/480/sequence.md?model=1182110), [All aircraft, 52 cases](https://openairdocs.org/ntsb-events/480/sequence.md) - [Landing: Loss of control in flight](https://openairdocs.org/ntsb-events/240); cases with it: [Bell 206-L4, 7 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=1182110), [All aircraft, 5,010 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Landing-flare/touchdown: Roll over](https://openairdocs.org/ntsb-events/097); cases with it: [Bell 206-L4, 1 case](https://openairdocs.org/ntsb-events/097/sequence.md?model=1182110), [All aircraft, 261 cases](https://openairdocs.org/ntsb-events/097/sequence.md) - [Landing-flare/touchdown: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Bell 206-L4, 8 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=1182110), [All aircraft, 10,154 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that he was performing external load long line hauling operations with a helicopter and was on a return leg with two empty nets. During the approach to a hilltop helipad, the pilot reported that he performed a normal approach, rather than a long line approach. Subsequently, the 100 foot long line snagged on a ridgeline and the helicopter jerked in an uncontrollable turn to the right, touched down right skid first, and rolled over. The pilot reported that he forgot that the long line was still attached. The tail boom was substantially damaged. The pilot did not report any mechanical malfunctions or failures with the helicopter that would have precluded normal operation. The operator submitted two operator/ owner safety recommendations to the National Transportation Safety Board investigator-in-charge. First, the operator revised the normal operation checklist. The revised checklist included a new "CARGO HOOK – CHECK" in both the BEFORE TAKEOFF and DESCENT AND LANDING checklist. Second, the chief pilot provided a copy of a memorandum to all employees that directs the use of an observer, when available, to observe the takeoff and landings and communicate any unsafe condition to the pilot via radio communication or hand signals. ## Factual narrative The pilot reported that he was performing external load long line hauling operations with a helicopter and was on a return leg with two empty nets. During the approach to a hilltop helipad, the pilot reported that he performed a normal approach, rather than a long line approach. Subsequently, the 100 foot long line snagged on a ridgeline and the helicopter jerked in an uncontrollable turn to the right, touched down right skid first, and rolled over. The pilot reported that he forgot that the long line was still attached. The tail boom was substantially damaged. The pilot did not report any mechanical malfunctions or failures with the helicopter that would have precluded normal operation. The operator submitted two operator/ owner safety recommendations to the National Transportation Safety Board investigator-in-charge. First, the operator revised the normal operation checklist. The revised checklist included a new "CARGO HOOK – CHECK" in both the BEFORE TAKEOFF and DESCENT AND LANDING checklist. Second, the chief pilot provided a copy of a memorandum to all employees that directs the use of an observer, when available, to observe the takeoff and landings and communicate any unsafe condition to the pilot via radio communication or hand signals. ## Aircraft - Registration: [N73AW](https://openairdocs.org/aircraft/N73AW), registered now, S/N 52115 (OpenAirDocs) - Reported make and model: BELL 206 (L4) - Registry model: [Bell 206-L4](https://openairdocs.org/model/bell-206-l4) (registry code 1182110) (OpenAirDocs) - Registry engine: [Allison 250-C30 series](https://openairdocs.org/engine/allison-250-c30-series) (registry code 03015, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: 52115 - Year built: 1995 - Airframe hours: 4338.8 - Engines: ALLISON 250-C30P 490 horsepower turbo shaft - Damage: Substantial damage - Flight: External load, Part 133 - Operator: Airwest Helicopters LLC. - Registered owner: Air Medical Services LLC. - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, March 9, 2016 - Departed: Supai, AZ - Destination: NONE, Hualapai, AZ - Flight plan: Company VFR - Equipment: Satellite tracking device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 56; injuries: minor; flight instructor, airline transport, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane, helicopter; medical: class 2, with waivers/limitations; last flight review March 22, 2016; seat: right; restraint: lap only; flight hours: 17,000 total, 12,000 in this make and model, 16,500 as pilot in command, 55 in the last 90 days, 10 in the last 30 days, 6 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 40° at 11 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 72 °F, dew point 7 °F - Altimeter: 30.35 inHg - Observed at: KGCN, 30 nm away ## 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 20160406007419A](https://openairdocs.org/incident/20160406007419A), Apr 6, 2016: Bell 206-L4, Supai, AZ, Substantial damage. On April 06, 2016 around 1610 MST, N73AW, BHT-206-L4 impacted the terrain after attempting to land at the hilltop helipad in Supai, Arizona. The helicopter was… ## Other investigations on N73AW (1) 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. - [NTSB WPR15LA177](https://openairdocs.org/ntsb/WPR15LA177), Jun 2, 2015: Bell 206 L4 (N73AW), Dewey, AZ, substantial damage. Probable cause: A total loss of engine power due to the failure of the No. 2 bearing, which resulted from a fractured separator. ## Docket (3 files) The files NTSB released with the investigation on May 12, 2016, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=92971. 812 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 656 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40440064&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Record of Conversation (Pilot in Command) (item 2, .PDF, 55 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40440065&FileExtension=.PDF&FileName=Record%20of%20Conversation%20(Pilot%20in%20Command)-Master.PDF - Accident Photo (Courtesy of Operator) (item 3, .PDF, 1 photo, 101 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40440066&FileExtension=.PDF&FileName=Accident%20Photo%20(Courtesy%20of%20Operator)-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.