# NTSB GAA17CA250: North Wing Uum Sport X2-N, N366DN, Boulder City, NV, April 30, 2017 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Data collection · Final report - Date: April 30, 2017, 08:00 local (15:00 UTC) - Place: Boulder City, NV - Coordinates: 35.866664, -114.943885 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=35.8667&lon=-114.9439&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report June 20, 2017 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 95084 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA17CA250 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/95084/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=95084 - Page: https://openairdocs.org/ntsb/GAA17CA250 ## Probable cause The student pilot’s exceedance of the weight-shift-control aircraft’s critical angle of attack and the flight instructor’s delayed remedial action and failure to maintain the proper airspeed after encountering localized turbulence during approach, which resulted in an aerodynamic stall. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Student/instructed pilot (probable cause); cases with it: [North Wing Uum SPORT X2-N, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=060006C), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [North Wing Uum SPORT X2-N, 1 case](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=060006C), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md) - [Action: delayed action](https://openairdocs.org/ntsb-findings/02041025): Personnel issues › Action/decision · Instructor/check pilot (probable cause); cases with it: [North Wing Uum SPORT X2-N, 1 case](https://openairdocs.org/ntsb-findings/02041025/cases.md?model=060006C), [All aircraft, 894 cases](https://openairdocs.org/ntsb-findings/02041025/cases.md) - [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [North Wing Uum SPORT X2-N, 1 case](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=060006C), [All aircraft, 1,681 cases](https://openairdocs.org/ntsb-findings/01062010/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: [North Wing Uum SPORT X2-N, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=060006C), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Attention/monitoring: monitoring other person](https://openairdocs.org/ntsb-findings/02021535): Personnel issues › Psychological · Instructor/check pilot (probable cause); cases with it: [North Wing Uum SPORT X2-N, 1 case](https://openairdocs.org/ntsb-findings/02021535/cases.md?model=060006C), [All aircraft, 200 cases](https://openairdocs.org/ntsb-findings/02021535/cases.md) - [Attention/monitoring: monitoring other person](https://openairdocs.org/ntsb-findings/02021535): Personnel issues › Psychological · Instructor/check pilot (probable cause); cases with it: [North Wing Uum SPORT X2-N, 1 case](https://openairdocs.org/ntsb-findings/02021535/cases.md?model=060006C), [All aircraft, 200 cases](https://openairdocs.org/ntsb-findings/02021535/cases.md) - [Wind: dust devil/whirlwind](https://openairdocs.org/ntsb-findings/03034060): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [North Wing Uum SPORT X2-N, 1 case](https://openairdocs.org/ntsb-findings/03034060/cases.md?model=060006C), [All aircraft, 38 cases](https://openairdocs.org/ntsb-findings/03034060/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing: Turbulence encounter](https://openairdocs.org/ntsb-events/360); cases with it: [North Wing Uum SPORT X2-N, 1 case](https://openairdocs.org/ntsb-events/360/sequence.md?model=060006C), [All aircraft, 423 cases](https://openairdocs.org/ntsb-events/360/sequence.md) - [Landing: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [North Wing Uum SPORT X2-N, 1 case](https://openairdocs.org/ntsb-events/240/sequence.md?model=060006C), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [North Wing Uum SPORT X2-N, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=060006C), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The student pilot of the weight-shift-control aircraft reported that, while practicing touch-and-go landings on a dried lake bed, the flight instructor was controlling the throttle inputs, and she "controlled the wing." She added that, just before the accident, she observed three dust devils to the east and that, during a final pass near the north end of the lake bed, they came upon "strong localized turbulence." The aircraft impacted the ground and rolled to the left. The flight instructor reported that, during the turbulence encounter "about 4-6 ft" above the ground, the "wing stalled," which resulted in a "hard nose wheel landing." The weight-shift-control aircraft sustained substantial damage to both wings. The flight instructor reported that there were no preaccident mechanical failures or malfunctions with the weigh-shift-control aircraft that would have precluded normal operation. The flight instructor reported that the wind was light and variable and that the temperature was 70°F at the accident location. A review of recorded data from the automated weather observation station located about 6 miles northeast of the accident site reported that, about the time of the accident, the wind was calm, and the temperature was 64°F. ## Factual narrative The student pilot of the weight-shift-control aircraft reported that while practicing touch-and-go landings on a dried lake bed, the flight instructor was controlling the throttle inputs and she "controlled the wing". She added that just before the accident, she observed three dust devils to the east and during a final pass near the north end of the lake bed, they came upon "strong localized turbulence". The aircraft impacted the ground and rolled to the left. The flight instructor reported that during the turbulence encounter "about 4-6 ft" above the ground, the "wing stalled" which resulted in a "hard nose wheel landing". The weight-shift-control aircraft sustained substantial damage to both wings. The flight instructor reported that there were no preaccident mechanical failures or malfunctions with the weigh-shift-control aircraft that would have precluded normal operation. The flight instructor reported the wind was light and variable, and the temperature was 70°F at the accident location. A review of recorded data from the automated weather observation station located about 6 miles northeast of the accident site reported that about the time of the accident the wind was calm and the temperature was 64°F. ## Aircraft - Registration: [N366DN](https://openairdocs.org/aircraft/N366DN), registered now, S/N LS7003, built 2008 (OpenAirDocs) - Reported make and model: NORTH WING UUM INC SPORT X2-N (NO SERIES) - Registry model: [North Wing Uum SPORT X2-N](https://openairdocs.org/model/north-wing-uum-sport-x2-n) (registry code 060006C) (OpenAirDocs) - Registry engine: [Rotax 582SER](https://openairdocs.org/engine/rotax-582ser) (registry code 55556, 2 cycle) (OpenAirDocs) - Category: Weight-shift - Serial number: LS7003 - Year built: 2008 - Airframe hours: 652 - Engines: Rotax 582 UL 65 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Airworthiness certificate: Special, Special light-sport (Special) - Last inspection: Annual, February 25, 2017 - Departed: BVU, BOULDER CITY, NV - Destination: BVU, BOULDER CITY, NV - Flight plan: VFR - Equipment: ADS-B, Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 62; injuries: minor; flight instructor, commercial, sport pilot; airplane ratings: single-engine land; medical: sport pilot; last flight review April 1, 2017; seat: rear; flight hours: 415 total, 393 in this make and model, 415 as pilot in command, 56 in the last 90 days, 23 in the last 30 days - Student pilot; age 61; injuries: minor; student; medical: sport pilot; seat: front; flight hours: 10 total, 10 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Temperature: 64 °F, dew point 16 °F - Altimeter: 30.18 inHg - Observed at: KBVU, 6 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 20170430004499A](https://openairdocs.org/incident/20170430004499A), Apr 30, 2017: North Wing Uum Inc SPORT X2-N, Boulder City, NV, Substantial damage. Aircraft encountered a dust devil while on short final to flare on approach for landing. Control of the aircraft was lost during the wind shift. The aircraft… ## Other investigations on N366DN (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 ANC18LA033](https://openairdocs.org/ntsb/ANC18LA033), Apr 25, 2018: North Wing Uum Sport X2-N (N366DN), Pahrump, NV, substantial damage. Probable cause: The pilot's improper landing flare, which resulted in a fractured engine mount sway bar and subsequent difficulty controlling the airplane, and his inadvertent application of throttle pedal during… ## Docket (3 files) The files NTSB released with the investigation on May 31, 2017, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=95084. 1.0 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1(Flight Instructor) (item 1, .PDF, 775 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40452695&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1(Flight%20Instructor)-Master.PDF - Student Pilot's Statement (item 2, .PDF, 32 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40452696&FileExtension=.PDF&FileName=Student%20Pilot%27s%20Statement-Master.PDF - Accident Photo (item 3, .PDF, 232 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40452697&FileExtension=.PDF&FileName=Accident%20Photo-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.