# NTSB CEN09CA007: Let Blanik, N48026, Gardner, KS, October 4, 2008 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: October 4, 2008, 13:15 local (18:15 UTC) - Place: Gardner, KS - Coordinates: 38.801109, -94.955276 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=38.8011&lon=-94.9553&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Glider tow event](https://openairdocs.org/ntsb-events/510) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report March 23, 2009 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA Kansas City FSDO - NTSB case key (mKey): 69155 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN09CA007 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/69155/pdf - Page: https://openairdocs.org/ntsb/CEN09CA007 ## Probable cause The pilot's decision to attempt a takeoff when the climb performance of the tow plane and the glider were inadequate. Contributing to the accident were the high density altitude and the terrain-induced turbulence. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Let BLANIK L-13, 1 case](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=1360306), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Performance/control parameters: climb rate](https://openairdocs.org/ntsb-findings/01062035): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Let BLANIK L-13, 1 case](https://openairdocs.org/ntsb-findings/01062035/cases.md?model=1360306), [All aircraft, 265 cases](https://openairdocs.org/ntsb-findings/01062035/cases.md) - [Temp/humidity/pressure: high density altitude](https://openairdocs.org/ntsb-findings/03031020): Environmental issues › Conditions/weather/phenomena · Effect on operation (probable cause); cases with it: [Let BLANIK L-13, 1 case](https://openairdocs.org/ntsb-findings/03031020/cases.md?model=1360306), [All aircraft, 278 cases](https://openairdocs.org/ntsb-findings/03031020/cases.md) - [Turbulence: terrain induced turbulence](https://openairdocs.org/ntsb-findings/03032010): Environmental issues › Conditions/weather/phenomena · Effect on operation (probable cause); cases with it: [Let BLANIK L-13, 1 case](https://openairdocs.org/ntsb-findings/03032010/cases.md?model=1360306), [All aircraft, 70 cases](https://openairdocs.org/ntsb-findings/03032010/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Glider tow event](https://openairdocs.org/ntsb-events/510) (defining event); cases with it: [Let BLANIK L-13, 1 case](https://openairdocs.org/ntsb-events/510/sequence.md?model=1360306), [All aircraft, 45 cases](https://openairdocs.org/ntsb-events/510/sequence.md) - [Takeoff: Turbulence encounter](https://openairdocs.org/ntsb-events/360); cases with it: [Let BLANIK L-13, 1 case](https://openairdocs.org/ntsb-events/360/sequence.md?model=1360306), [All aircraft, 423 cases](https://openairdocs.org/ntsb-events/360/sequence.md) - [Initial climb: Miscellaneous/other](https://openairdocs.org/ntsb-events/900); cases with it: [Let BLANIK L-13, 1 case](https://openairdocs.org/ntsb-events/900/sequence.md?model=1360306), [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) - [Other: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Let BLANIK L-13, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=1360306), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The private pilot was conducting a normal aero-tow takeoff in a glider from runway 21, a 2,154-foot-long turf runway. The tow plane pilot and the glider pilot reported that they both became airborne at approximately 40 knots. Both pilots released the tow rope at the end of the runway when it became obvious that the climb performance of the glider and the tow plane was insufficient to accelerate or to climb out of ground effect. The glider then crashed into the fence at the end of the runway. Weather at the time of the accident was 10 miles visibility, clear of clouds, winds from 150 degrees at 9 knots, with a temperature of 74 degrees and dew point of 57 degrees. Density altitude was calculated as 2,260 feet. Other pilots familiar with this airport report that often in crosswind operations there is induced turbulence from the trees along left side of the departure end of runway 21. ## Factual narrative The private pilot was conducting a normal aero tow takeoff in a glider from the 2,154 foot long turf runway 21. The tow plane pilot and the glider pilot both reported that they both became airborne at approximately 40 knots and both pilots released the tow rope at the end of the runway when it became obvious that the climb performance of the glider and the tow plane was insufficient to accelerate or to climb out of ground effect. The glider then crashed into the fence at the end of runway 21. Weather reported by at the time of the accident was 10 miles visibility, clear of clouds, winds from 150 at 9 knots, with a temperature of 74 degrees and dew point of 57 degrees. Density altitude was calculated as 2,260 feet. Other pilots familiar with this airport report that in crosswind operations there is frequently induced turbulence from the trees along left side of the departure end of runway 21. ## Aircraft - Registration: [N48026](https://openairdocs.org/deregistered/N48026-2010-06-04), registration cancelled 2010-06-04, S/N 026021, built 1975 (OpenAirDocs) - Reported make and model: Let Blanik (L-13) - Registry model: [Let BLANIK L-13](https://openairdocs.org/model/let-blanik-l-13) (registry code 1360306) (OpenAirDocs) - Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs) - Category: Glider - Serial number: 026021 - Airframe hours: 1859 - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 17, 2008 - Departed: K34, Gardner, KS - Destination: K34, Gardner, KS - Flight plan: Unknown - Airport: K34, Gardner Municipal Airport, runway 21, 2,154 × 80 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 56; injuries: none; private; airplane ratings: single-engine land; medical: class 2, with waivers/limitations; last flight review September 28, 2008; seat: front; flight hours: 479 total, 13 in this make and model, 409 as pilot in command, 19 in the last 90 days, 3 in the last 30 days ## Weather - Conditions: Visual (VMC), Dawn - Wind: 150° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 73 °F, dew point 57 °F - Altimeter: 30.03 inHg - Observed at: KIXD, 5 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 20081004848339A](https://openairdocs.org/incident/20081004848339A), Oct 4, 2008: Let L13BLANIK, Gardner, KS, Substantial damage. (-23) The events surrounding this accident involved a glider aero tow launch from runway 21 in cross wind conditions at Gardner municipal airport (K34),… 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.