# NTSB CEN22LA279: Let L-23 Super Blanik, N364BA, Yoder, KS, June 22, 2022 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Class 4 · Limited · Final report - Date: June 22, 2022, 11:30 local (16:30 UTC) - Place: Yoder, KS - Coordinates: 37.939714, -97.904686 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=37.9397&lon=-97.9047&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach-VFR pattern base: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241) - Highest injury: Serious injuries - Injuries: 1 serious, 1 minor - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Central Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 105339 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN22LA279 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/105339/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=105339 - Page: https://openairdocs.org/ntsb/CEN22LA279 ## Probable cause The pilot's encounter with sinking air conditions that resulted in a loss of lift and a subsequent loss of control. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters](https://openairdocs.org/ntsb-findings/01062000): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Let L-23 SUPER BLANIK, 1 case](https://openairdocs.org/ntsb-findings/01062000/cases.md?model=1360308), [All aircraft, 1,269 cases](https://openairdocs.org/ntsb-findings/01062000/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 base: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241) (defining event); cases with it: [Let L-23 SUPER BLANIK, 5 cases](https://openairdocs.org/ntsb-events/241/sequence.md?model=1360308), [All aircraft, 1,529 cases](https://openairdocs.org/ntsb-events/241/sequence.md) - [Approach-VFR pattern base: Loss of lift](https://openairdocs.org/ntsb-events/500); cases with it: [Let L-23 SUPER BLANIK, 5 cases](https://openairdocs.org/ntsb-events/500/sequence.md?model=1360308), [All aircraft, 252 cases](https://openairdocs.org/ntsb-events/500/sequence.md) ## Analysis The flight instructor reported that after demonstrating maneuvers he noticed that the glider had quickly descended to pattern altitude, so he proceeded into the traffic pattern. He slowed the glider to minimum sink airspeed and then turned onto the base leg about 200 to 250 ft above ground level. During the base leg turn, the glider continued to turn and descend, and the flight instructor was unable to maintain control. The glider impacted terrain short of the runway and sustained substantial damage to the fuselage, empennage, and both wings. The flight instructor reported that there were no preimpact mechanical malfunctions or failures with the glider that would have precluded normal operation. The flight instructor reported that there was sinking air in the flight area. ## Aircraft - Registration: [N364BA](https://openairdocs.org/aircraft/N364BA), registered now, S/N 008706, built 2000 (OpenAirDocs) - Reported make and model: LET L-23 SUPER BLANIK - Registry model: [Let L-23 SUPER BLANIK](https://openairdocs.org/model/let-l-23-super-blanik) (registry code 1360308) (OpenAirDocs) - Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs) - Category: Glider - Serial number: 008706 - Year built: 2000 - Airframe hours: 4420.9 - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Civil Air Patrol Inc - Registered owner: Civil Air Patrol Inc - Airworthiness certificate: Standard, Utility; Standard, Normal - Last inspection: Annual, May 4, 2022 - Airport: SN76, Sunflower Aerodrome Gliderport, runway 17, 7,000 × 200 ft, asphalt - Equipment: ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 71; injuries: serious; commercial, flight instructor; airplane ratings: single-engine land; instrument ratings: airplane; medical: basicmed, without waivers/limitations; last flight review June 22, 2021; seat: rear; restraint: 5-point; flight hours: 6,143 total, 359 in this make and model, 5,963 as pilot in command, 0 in the last 24 hours - Student pilot; age 15; injuries: minor; seat: front; restraint: 5-point ## Weather - Conditions: Visual (VMC), Day - Wind: 90° at 10 knots - Visibility: 10 statute miles - Temperature: 79 °F, dew point 70 °F - Altimeter: 30.21 inHg - Observed at: KHUT, 8 nm away - METAR: KHUT 221652Z 09010KT 10SM FEW019 26/21 A3021 RMK AO2 SLP207 T02610211 ## 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 20220622010899A](https://openairdocs.org/incident/20220622010899A), Jun 22, 2022: Let L-23 SUPER BLANIK, Yoder, KS, Substantial damage. Pilot was intending to release from the tow plane at 4500 MSL, but clouds and haze were obscuring the horizon making it difficult for new student to see… ## Docket (2 files) The files NTSB released with the investigation on July 22, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=105339. 7.1 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 5.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14152845&FileExtension=pdf&FileName=6120%20-%20Pilot_Redacted-Rel.pdf - Photos (item 2, PDF, 2 pages, 2 photos, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14153081&FileExtension=pdf&FileName=Docket%20photos-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.