# NTSB CEN18CA291: Quad City Challenger, N1666R, Oshkosh, WI, July 23, 2018 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: July 23, 2018, 09:50 local (14:50 UTC) - Place: Oshkosh, WI - Coordinates: 43.966945, -88.560836 - Nearby events: https://openairdocs.org/map.md?lat=43.9669&lon=-88.5608&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach-VFR pattern final: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report March 18, 2019 - Report: Approved by Office Director - NTSB office: Central Region - NTSB case key (mKey): 97856 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN18CA291 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/97856/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=97856 - Page: https://openairdocs.org/ntsb/CEN18CA291 ## Probable cause The pilot’s failure to maintain adequate airspeed during the base to final turn and his exceedance of the airplane’s critical angle of attack, 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 · Pilot (probable cause); cases with it: [Holtz Rodney R CHALLENGER II, 2 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=059041F), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters](https://openairdocs.org/ntsb-findings/01062000): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Holtz Rodney R CHALLENGER II, 1 case](https://openairdocs.org/ntsb-findings/01062000/cases.md?model=059041F), [All aircraft, 1,269 cases](https://openairdocs.org/ntsb-findings/01062000/cases.md) - [Object/animal/substance: fence/fence post](https://openairdocs.org/ntsb-findings/03022047): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Holtz Rodney R CHALLENGER II, 1 case](https://openairdocs.org/ntsb-findings/03022047/cases.md?model=059041F), [All aircraft, 313 cases](https://openairdocs.org/ntsb-findings/03022047/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach-VFR pattern final: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Holtz Rodney R CHALLENGER II, 2 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=059041F), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Holtz Rodney R CHALLENGER II, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=059041F), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The airplane was landing on the ultralight field when the accident occurred. The pilot stated that she made a wide base to final turn because she was unsure about the placement of the runway. Although the pilot added power, the airplane entered a left descending turn until the left wing contacted the ground near the beginning of the runway's displaced threshold. The airplane then spun left and slid rearward on the ground until it contacted a chain-link fence. The pilot reported that there were no mechanical anomalies with the airplane that would have precluded normal operation. The pilot's statement, along with a ground-based video of the accident, revealed that the pilot failed to maintain adequate airspeed and exceeded the airplane's critical angle of attack during the base to final turn, which resulted in an aerodynamic stall. ## Factual narrative The pilot reported that she made a wide turn from base leg to final approach because she did not know exactly where the runway was placed. She stated she banked the airplane to line up with the runway and was still in a bank when the airplane approached the runway threshold. She added power to keep from getting too low, but the airplane contacted the ground and spun around, coming to a stop up against a chain-link fence.The left wing, rudder, and elevator sustained substantial damage. The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation. The experimental amateur built airplane was landing on ultralight runway 33 during Experimental Aircraft Association (EAA) AirVenture when the accident occurred. The EAA AirVenture Notice to Airmen (NOTAM) contained a diagram showing the approach route for airplanes landing on runway 33. The procedure is to follow the northbound road at the east end of Ripple Road then make an approximate 30° left turn near the runway threshold to align with the runway. The west side of the northbound road is bordered by trees. The accident airplane contacted the ground near the beginning of the displaced threshold for the runway. The accident was captured on a ground-based video which showed the airplane in a left descending turn as it approached the runway. The airplane continued in the left turn until the left wing contacted the ground. The left main gear and nose gear then contacted the ground followed shortly thereafter by the right main gear. The airplane then slid rearward and spun to the left coming to rest after the tail contacted the fence. The airplane came to rest on a heading of 45°. ## Aircraft - Registration: [N1666R](https://openairdocs.org/aircraft/N1666R), registered now, S/N CH2-0899-1897, built 2008 (OpenAirDocs) - Reported make and model: Quad City CHALLENGER (II) - Registry model: [Holtz Rodney R CHALLENGER II](https://openairdocs.org/model/holtz-rodney-r-challenger-ii) (registry code 059041F) (OpenAirDocs) - Registry engine: [Rotax 503 DCDI](https://openairdocs.org/engine/rotax-503-dcdi) (registry code 55566, 2 cycle) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: CH2-0899-1897 - Year built: 2008 - Airframe hours: 348 - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, July 15, 2018 - Departed: Y50, Wautoma, WI - Destination: OSH, Oshkosh, WI - Airport: OSH, Wittman Rgnl, runway 33, 1,200 × 100 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 50; injuries: none; private, flight instructor; airplane ratings: single-engine sea, single-engine land; medical: class 3, with waivers/limitations; last flight review July 11, 2016; seat: front; flight hours: 874 total, 299 in this make and model, 798 as pilot in command, 50 in the last 90 days, 18 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 350° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: 5,000 ft broken - Temperature: 72 °F, dew point 63 °F - Altimeter: 29.96 inHg - Observed at: KOSH, 1 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 20180723017829A](https://openairdocs.org/incident/20180723017829A), Jul 23, 2018: Holtz Rodney R CHALLENGER II, Oshkosh, WI, Substantial damage. Pilot was on landing approach and made wide turn to runway. Aircraft stalled hit the ground and spun until hitting a fence. ## Other investigations on N1666R (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 ERA25LA063](https://openairdocs.org/ntsb/ERA25LA063), Nov 20, 2024: Holtz Rodney R Challenger II (N1666R), Concord, NH, substantial damage. Probable cause: The pilot’s failure to maintain directional control and eventual stall/mush of the airplane while trying to secure an open door in flight. ## Docket (5 files) The files NTSB released with the investigation on September 25, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=97856. 15.8 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=40466894&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - NOTAM - Excerpt (item 2, .PDF, 328 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40466896&FileExtension=.PDF&FileName=NOTAM%20-%20Excerpt-Master.PDF - Photo Array (item 3, .PDF, 4 photos, 5.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40466897&FileExtension=.PDF&FileName=Photo%20Array-Master.PDF - Photo Array - EAA Photos (item 4, .PDF, 7 photos, 2.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40466899&FileExtension=.PDF&FileName=Photo%20Array%20-%20EAA%20Photos-Master.PDF - Video - EAA (item 5, AVI, 5.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40466906&FileExtension=avi&FileName=Video%20-%20EAA-Master 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.