# NTSB DEN93LA085: Let L-13, N48069, Durango, CO, July 24, 1993

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: July 24, 1993, 14:50 local (20:50 UTC)
- Place: Durango, CO
- Coordinates: 37.270877, -107.880043 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=37.2709&lon=-107.8800&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 2 minor
- Status: Completed, report November 19, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 18302
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN93LA085
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/18302/pdf
- Page: https://openairdocs.org/ntsb/DEN93LA085

## Probable cause

THE FAILURE OF THE TOW PLANE PILOT TO WARN THE GLIDER PILOT THAT HE WAS RELEASING THE TOW LINE.  A FACTOR WAS:  AN INADVERTENT STALL BY THE PILOT IN COMMAND.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of control - in flight, takeoff - initial climb
  - safety advisory - not issued, pilot of other aircraft (cause)
  - stall - inadvertent, pilot in command (contributing factor)
- In flight collision with object, descent - uncontrolled
  - object - airport facility

## Analysis

BOTH THE GLIDER AND TOW PLANE PILOTS AGREED THAT IF THE GLIDER WAS AIRBORNE BY MIDFIELD, THE GLIDER PILOT WOULD RELEASE THE TOW. TAKEOFF WAS NORMAL AND THE GLIDER WAS AIRBORNE BEFORE MIDFIELD. THE TOW PLANE PILOT, HOWEVER, ENCOUNTERED A WIND GUST OR SHEAR THAT LIFTED THE TOW PLANE, THEN CAUSED IT TO SETTLE TO THE GROUND. HE SENSED HE WAS NOT ACCELERATING AND GAINING ALTITUDE AS HE SHOULD. HE RELEASED THE TOW LINE. THE GLIDER PILOT FOLLOWED THE TOW PLANE TO MAINTAIN PROPER TOW POSITION. AS THE TOW PLANE CLIMBED OUT, HE REALIZED HE HAD BEEN RELEASED AND SAW HIS AIRSPEED DETERIORATING. THE RIGHT WING BEGAN TO STALL AND DROP. HE ATTEMPTED TO LAND IN AN EMPTY PARKING LOT, BUT THE RIGHT WING STRUCK THE RAILING OF AN OBSERVATION DECK. THE TOW PLANE PILOT SAID HE FAILED TO WARN THE GLIDER PILOT ABOUT THE TOW RELEASE BECAUSE HE ASSUMED HE WOULD SEE AND FEEL THE RELEASE, AND HE DID NOT WANT TO DISTRACT HIM FROM FLYING AND GLIDER.

## Aircraft

- Registration: [N48069](https://openairdocs.org/deregistered/N48069-2008-06-06), registration cancelled 2008-06-06, S/N 026129, built 1975 (OpenAirDocs)
- Reported make and model: LET 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: 026129
- Airframe hours: 2102
- Engines: unknown
- Damage: Destroyed
- Flight: Personal, Part 91
- Operator: St. Clair, Lavern D., doing business as Durango Soaring Club
- Registered owner: St. Clair, Lavern D.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, May 11, 1993, 90 hours before
- Departed: CD82
- Destination: CD82
- Airport: CD82, Val Air Gliderport, runway 35, 3,500 × 240 ft, grass/turf

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 61; commercial; airplane ratings: multi-engine land, single-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: rear; flight hours: 3,869 total, 30 in this make and model, 3,869 as pilot in command, 68 in the last 90 days, 54 in the last 30 days, 7 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 330° at 10 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 75 °F, dew point 41 °F
- Altimeter: 30.00 inHg

## 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 19930724025289A](https://openairdocs.org/incident/19930724025289A), Jul 24, 1993: Let L13BLANIK, Durango, CO, Destroyed. Turbulence on glider tow. Tow pilot released tow to clear trees. Glider pilot tried to land in parking lot.

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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