# NTSB WPR10CA015: Let Blanik L-13, N948LC, Llano, CA, October 11, 2009

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Data collection · Final report
- Date: October 11, 2009, 10:45 local (17:45 UTC)
- Place: Llano, CA
- Coordinates: 34.484443, -117.826385
- Nearby events: https://openairdocs.org/map.md?lat=34.4844&lon=-117.8264&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Defining event: [Approach: Loss of control in flight](https://openairdocs.org/ntsb-events/240)
- Highest injury: Serious injuries
- Injuries: 1 serious
- Status: Completed, report March 3, 2010
- Report: Approved by Office Director
- NTSB office: Western Pacific Region
- Parties: Federal Aviation Administration
- NTSB case key (mKey): 74889
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR10CA015
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/74889/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=74889
- Page: https://openairdocs.org/ntsb/WPR10CA015

## Probable cause

The student pilot's improper use of the airbrakes while on approach for landing.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Wing structure: spoilers](https://openairdocs.org/ntsb-findings/01035755): Aircraft › Aircraft structures · Incorrect use/operation (probable cause); cases with it: [Let BLANIK L-13, 1 case](https://openairdocs.org/ntsb-findings/01035755/cases.md?model=1360306), [All aircraft, 8 cases](https://openairdocs.org/ntsb-findings/01035755/cases.md)
- [Experience/qualifications: total experience](https://openairdocs.org/ntsb-findings/02031015): Personnel issues › Experience/knowledge · Student/instructed pilot; cases with it: [Let BLANIK L-13, 1 case](https://openairdocs.org/ntsb-findings/02031015/cases.md?model=1360306), [All aircraft, 126 cases](https://openairdocs.org/ntsb-findings/02031015/cases.md)
- [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Student/instructed pilot (probable cause); cases with it: [Let BLANIK L-13, 1 case](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=1360306), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Approach: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event); cases with it: [Let BLANIK L-13, 1 case](https://openairdocs.org/ntsb-events/240/sequence.md?model=1360306), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md)
- [Approach: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Let BLANIK L-13, 3 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=1360306), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)

## Analysis

In a written statement, the certified flight instructor (CFI) reported that the student pilot had accomplished five dual instructional flights earlier that day. The CFI then cleared the student pilot for a solo flight. The glider was attached to a tow airplane, and the takeoff and tow were normal. The student released the glider at 2,000 feet above ground level (agl). The student used the airbrakes to descend to pattern altitude (1,000 feet agl). The CFI reported that the student forgot to close the airbrakes upon reaching traffic pattern altitude and the glider continued to descend rapidly. The student pilot maintained a 45-degree entry to the downwind leg of the runway and the glider impacted trees about 500 feet short of the airport, substantially damaging the wings, fuselage, and right horizontal stabilizer drag spar. When the CFI arrived on-scene the airbrakes were in the open position. There was no report of a mechanical failure or malfunction with the glider at the time of the accident.

## Factual narrative

In a written statement, the certified flight instructor (CFI) reported that the student pilot had accomplished five dual instructional flights earlier that day. The CFI then cleared the student pilot for a solo flight. The glider was attached to a tow airplane, and the takeoff and tow were normal. The student released the glider at 2,000 feet above ground level (agl). The student used the airbrakes to descend to pattern altitude (1,000 feet agl). The CFI reported that the student forgot to close the airbrakes upon reaching traffic pattern altitude and the glider continued to descend rapidly. The student pilot maintained a 45-degree entry to the downwind leg of the runway and the glider impacted Joshua trees about 500 feet short of the airport, substantially damaging the wings, fuselage, and right horizontal stabilizer drag spar. When the CFI arrived on-scene, the airbrakes were in the open position. There was no report of a mechanical failure or malfunction with the glider at the time of the accident.

## Aircraft

- Registration: [N948LC](https://openairdocs.org/deregistered/N948LC-2017-04-18), registration cancelled 2017-04-18, S/N 026037 (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)
- Category: Glider
- Serial number: 026037
- Airframe hours: 3165
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Southern California Soaring Academy
- Registered owner: Price L Cook
- Airworthiness certificate: Standard, Utility; Standard, Normal; Standard, Aerobatic
- Last inspection: 100 hour, September 11, 2009
- Departed: 46CN, Llano, CA
- Destination: 46CN, Llano, CA
- Airport: 46CN, Crystal Airport

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Student pilot; age 67; injuries: serious; student; seat: front; flight hours: 52 total, 52 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: 220° at 11 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 66 °F, dew point 41 °F
- Altimeter: 29.84 inHg
- Observed at: PMD, 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 20091011022499A](https://openairdocs.org/incident/20091011022499A), Oct 11, 2009: Let L13BLANIK, Llano, CA, Substantial damage. Student had 5 dual flights on day of the accident. On first supervised solo flight, student stated that the aerotow was normal and at 2,000 feet AGL, he…

## Docket (2 files)

The files NTSB released with the investigation on November 18, 2009, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=74889. 1.0 MB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 - Pilot (item 1, .PDF, 182 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40321465&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%20-%20Pilot-Redacted.PDF
- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 - CFI (item 2, .PDF, 822 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40321464&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%20-%20CFI-Redacted.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.

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