# NTSB WPR20LA157: Cub Crafters CCK-1865, N303KP, Valley Center, CA, June 1, 2020 - Type: NTSB accident investigation - Classification: Accident · Fatal · Class 3 · Limited · Final report - Date: May 31, 2020, 17:57 local (Jun 1, 2020, 00:57 UTC) - Place: Valley Center, CA - Coordinates: 33.284999, -117.013336 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.2850&lon=-117.0133&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Fatal - Injuries: 1 fatal, 1 serious - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: CubCrafters, Federal Aviation Administration - NTSB case key (mKey): 101349 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR20LA157 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/101349/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=101349 - Page: https://openairdocs.org/ntsb/WPR20LA157 ## Probable cause The pilot's exceedance of the airplane's critical angle of attack while maneuvering at low altitude, which resulted in an aerodynamic stall and subsequent loss of control. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Richard Michael Krause CCK-1865, 1 case](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=056308G), [All aircraft, 1,681 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md) - [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Richard Michael Krause CCK-1865, 1 case](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=056308G), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Richard Michael Krause CCK-1865, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=056308G), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/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: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Richard Michael Krause CCK-1865, 1 case](https://openairdocs.org/ntsb-events/240/sequence.md?model=056308G), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Maneuvering-low-alt flying: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241); cases with it: [Richard Michael Krause CCK-1865, 1 case](https://openairdocs.org/ntsb-events/241/sequence.md?model=056308G), [All aircraft, 1,529 cases](https://openairdocs.org/ntsb-events/241/sequence.md) ## Analysis The pilot was circling over a residence during a local flight. Witness video and flight tracking information indicated that, after completing a 360° turn, the airplane’s bank angle exceeded 40°. During the final turn, about 200 ft above ground level (agl), the airplane’s airspeed dropped below the published stall speed and the airplane stalled, entering a nose-low descent toward the ground. A sound spectrum analysis revealed that the engine was producing power at the time of the accident, and recorded engine data revealed no evidence of anomalies. Control continuity was confirmed. The circumstances of the accident are consistent with the pilot’s exceedance of the airplane’s critical angle of attack while maneuvering at low altitude, which resulted in an aerodynamic stall, loss of control, and impact with terrain. ## Factual narrative On May 31, 2020, at 1757 Pacific daylight time, an experimental Cub Crafters CCK-1865, N303KP, was substantially damaged when it was involved in an accident near Valley Center, California. The pilot sustained fatal injuries and the passenger was seriously injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. On the day of the accident, the pilot’s family was having a gathering at his hangar. The pilot took family members on four 20-minute flights. The accident flight, the fifth flight of the day, the pilot planned to take his niece to circle over her friend’s house. She was seated in the rear seat, and he secured her seat belt. The airplane departed from Lake Wohlford Resort Airport, Escondido, California, about 1735 and flew northwest. Track data were consistent with the airplane maneuvering around a building briefly before heading east. (see figure 1.) Figure 1: Flight Path At 1752, the airplane began to circle around the accident site. The calculated calibrated airspeed slowed to between 40 and 50 kts as the airplane completed a series of left and right turns between 100 ft to 300 ft above ground level (agl). Starting at 1756, the airplane completed a 180° right turn and climbed 100 ft while the calibrated airspeed dropped to near 35 kts. About 1756:30, the airspeed was above 45 kts and the airplane began a left turn. The airplane completed a full 360° turn and was continuing to turn and descend with a bank angle greater than 40° left-wing-down. The last recorded data point was at 1757:13 and was located about 100 ft from the accident site. (see figure 2.) Figure 2: Flight Path Around Accident Site Several witnesses on the ground recorded video of the airplane maneuvering. Just before impact, the airplane pitched up in a nose-high attitude. About 5 seconds later, the airplane rolled left along its longitudinal axis with the left wing dropping down toward the ground. The airplane then dropped nose-low, pointing directly toward the ground. (see figure 3.) Figure 3: Excerpts of the Video Prior to Impact The airplane manufacturer provided estimated power-off stall speed versus bank angle information. The airplane’s wings-level, no flaps, power-off stall speed was reported to be 42 kts calibrated airspeed. During the final minutes of the flight, the airplane’s calibrated airspeed was between 40 and 50 kts while circling. Using the relationship between bank angle and stall speed for the clean, no-flaps configuration, the stall speed was calculated. (see figure 4.) The power-on speed increases the stall margin several kts as compared to the reported power-off stall speeds. After 1757, the airplane’s turn tightened, increasing the bank angle, as the airplane’s speed continued to decrease. The airplane at this point was less than 200 ft above the terrain. It impacted the ground shortly after. Figure 4: Altitude (msl), Calibrated Airspeed, and Bank Angle Compared to Power-off Stall Speed A sound spectrumanalysis revealed that when the airplane was at about 1,850 ft msl the engine was operating at the recommended speed between around 1,800-2,000 rpm. Engine monitor data revealed that the cylinder head temperatures and exhaust gas temperatures all remained within normal ranges until the end of the data. The last recorded point showed an airspeed of 28 kts and a vertical speed in excess of -300 ft per minute. The Federal Aviation Administration (FAA) inspectors who responded to the accident site stated that they confirmed flight control continuity. Conditions at Accident Site: Visual (VMC) Condition of Light: Day Observation Facility, Elevation: KCRQ,328 ft msl Distance from Accident Site: 16 Nautical Miles Observation Time: 17:59 Local Direction from Accident Site: 235° Lowest Cloud Condition: Clear Visibility 10 miles Lowest Ceiling: None Visibility (RVR): Wind Speed/Gusts: 4 knots / Turbulence Type Forecast/Actual: None / None Wind Direction: 190° Turbulence Severity Forecast/Actual: N/A / N/A Altimeter Setting: 29.7 inches Hg Temperature/Dew Point: 24°C / 14°C Precipitation and Obscuration: No Obscuration; No Precipitation Departure Point: Escondido, CA (8CL1) Type of Flight Plan Filed: None ## Aircraft - Registration: [N303KP](https://openairdocs.org/deregistered/N303KP-2022-09-08), registration cancelled 2022-09-08, S/N CCK-1865-0013, built 2011 (OpenAirDocs) - Reported make and model: Cub Crafters CCK-1865 - Registry model: [Richard Michael Krause CCK-1865](https://openairdocs.org/model/richard-michael-krause-cck-1865) (registry code 056308G) (OpenAirDocs) - Registry engine: [Cubcrafter CC340](https://openairdocs.org/engine/cubcrafter-cc340) (registry code 18050, 4 cycle) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: CCK-1865-0013 - Year built: 2011 - Airframe hours: 437.9 - Engines: Continental Titan 340CC 180 horsepower reciprocating - Damage: Substantial damage - Fire: On-Ground - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, June 1, 2019 - Departed: 8CL1, Escondido, CA - Destination: 8CL1, Escondido, CA - Equipment: Stall warning system, ADS-B, Electronic primary flight display ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 57; injuries: fatal; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; last flight review August 4, 2018; seat: front; restraint: 4-point; toxicology performed; flight hours: 1,545 total, 269 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 190° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 75 °F, dew point 57 °F - Altimeter: 29.70 inHg - Observed at: KCRQ, 16 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 20200531004239A](https://openairdocs.org/incident/20200531004239A), May 31, 2020: Richard Michael Krause CCK-1865, Valley Center, CA, Destroyed, 1 fatal. On may 31, 2020 at 1757 pacific daylight time, an experimental cub crafters cck-, N303KP, was recorder on cellphone video flying low and slow over a… ## Docket (13 files) The files NTSB released with the investigation on May 4, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=101349. 11.8 MB in all. - Electronic devices - specialist's factual report (item 1, PDF, 10 pages, 2.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11926862&FileExtension=pdf&FileName=WPR20LA157%20Electronic%20Devices%20-%20Specialist%27s%20Factual%20Report-Rel.pdf - Attachment 1 to electronic devices - specialist's factual report (item 2, CSV, 25 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11926486&FileExtension=csv&FileName=Attachment%201%20to%20Electronic%20Devices%20-%20Specialist%27s%20Factual%20Report-Rel.csv - Aircraft performance study (item 3, PDF, 7 pages, 3.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11949100&FileExtension=pdf&FileName=WPR20LA157_Performance_Study-Rel.pdf - Video study (item 4, PDF, 13 pages, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13595045&FileExtension=pdf&FileName=Valley_Center_Video_Study_final-Rel.pdf - Record of conversations (item 5, PDF, 3 pages, 133 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13646044&FileExtension=pdf&FileName=Z%20-%20Attachment%2003%20-%20Record%20of%20Conversations-Rel.pdf - GPS track (plot) (item 6, KMZ, 35 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13572826&FileExtension=kmz&FileName=Radar%20Data-Rel.kmz - Radar data (all) (item 7, PDF, 18 pages, 187 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13572380&FileExtension=pdf&FileName=Z%20-%20Attachment%2006%20-%20Radar%20Data%20(all)-Rel.pdf - Dynon data (item 8, PDF, 33 pages, 135 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13646617&FileExtension=pdf&FileName=Z%20-%20Attachment%2005%20-%20Dynon%20(raw%20and%20sorted)-Rel.pdf - Dynon data plots and graphs (item 9, PDF, 6 pages, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13646024&FileExtension=pdf&FileName=Z%20-%20Attachment%2006%20-%20Dynon%20data%20plotted-Rel.pdf - Investigation support material supplement (item 10, PDF, 9 pages, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13643201&FileExtension=pdf&FileName=Z%20-%20Attachment%2001%20-%20Investigative%20Support%20Information-Rel.pdf - Autopsy summary (item 11, PDF, 1 page, 112 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13747092&FileExtension=pdf&FileName=Z%20-%20Attachment%2009%20-%20Autopsy%20Summary-Rel.pdf - Statement of party representatives to NTSB investigation (item 12, PDF, 1 page, 250 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13646412&FileExtension=pdf&FileName=Z%20-%20Attachment%2007%20-%20Party%20Form_Redacted-Rel.pdf - Toxicological report (item 13, PDF, 1 page, 174 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13571976&FileExtension=pdf&FileName=Z%20-%20Attachment%2003%20-%20Tox_redacted-Rel.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.