# NTSB LAX93LA326: Pilatus B4-PC11AF, N205AS, Truckee, CA, August 17, 1993

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: August 17, 1993, 15:15 local (22:15 UTC)
- Place: Truckee, CA
- Location: 39.3201° N, 120.1396° W: Placed by OpenAirDocs at TRUCKEE-TAHOE (TRK), within about a mile (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=39.3201&lon=-120.1396&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious
- Status: Completed, report August 1, 1994
- Report: Approved by Office Director
- NTSB case key (mKey): 28451
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX93LA326
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/28451/pdf
- Page: https://openairdocs.org/ntsb/LAX93LA326

## Probable cause

FAILURE OF THE PILOT TO CONDUCT ADEQUATE PREFLIGHT CHECKS WHICH RESULTED IN THE GLIDER TAKING OFF WITH A FRAYED RELEASE HOOK CABLE, THE PILOT'S FAILURE TO MAINTAIN AIRSPEED, AND THE INADVERTENT STALL.

## Sequence of events

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

- Airframe/component/system failure/malfunction, takeoff - initial climb
  - glider launch/tow equipment - frayed (contributing factor)
  - aircraft preflight - inadequate, pilot in command (cause)
- Loss of control - in flight, takeoff - initial climb
  - aborted takeoff - attempted, pilot in command
  - airspeed - not maintained, pilot in command (cause)
  - stall - inadvertent, pilot in command
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - runway

## Analysis

THE PILOT FAILED TO DISCOVER A FRAYED TOW RELEASE CABLE DURING  THE PREFLIGHT CHECK.  THE CABLE WAS BINDING WHEN THE PILOT  ATTEMPTED TO ABORT HIS TAKEOFF.  THE PILOT INADVERTENTLY  STALLED THE GLIDER AND IMPACTED THE RUNWAY SURFACE IN A NOSE  DOWN, RIGHT WING LOW ATTITUDE.

## Factual narrative

On August 17, 1993, at 1515 hours Pacific daylight time, a        Pilatus B4-PC11AF glider, N205AS, collided with the runway        surface at the Truckee Tahoe Airport, Truckee, California, after  experiencing an inflight loss of control during an aero tow.  The pilot was beginning a local visual flight rules personal flight.  The glider, operated by Ames Soaring Club, Livermore, California, sustained substantial damage.  The certificated private pilot,    the sole occupant, received serious injuries.  Visual             meteorological conditions prevailed.

The glider was being towed behind an airplane.  Witnesses         observed some erratic movement by the glider, followed by a tow   line release by the glider.  The pilot tried to make a 180 degree turn back to the runway.  The glider then lost control and        collided with the runway in a nose down, right wing low attitude.

The glider was transported to J.J. Glider Repair, Placerville     California, for examination.  The tow release cable was inspected by the FAA Aviation Safety Inspector from the Reno Flight         Standards District Office.  The inspector reported he found that  the cable was frayed and 50 percent of the strands were broken    where the cable exits the instrument panel.  He stated that the   frayed and broken strands allowed the cable to bind in the        housing which prevented complete locking of the tow hook.

## Aircraft

- Registration: [N205AS](https://openairdocs.org/deregistered/N205AS-2014-09-10), registration cancelled 2014-09-10, S/N 264, built 1977 (OpenAirDocs)
- Reported make and model: PILATUS B4-PC11AF
- Registry model: [Pilatus B4-PC11AF](https://openairdocs.org/model/pilatus-b4-pc11af) (registry code 7090103) (OpenAirDocs)
- Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs)
- Category: Glider
- Serial number: 264
- Engines: unknown
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Ames Soaring Club
- Airworthiness certificate: Special, Experimental (Special)
- Departed: TRK
- Destination: TRK
- Airport: TRK, Truckee-Tahoe, runway 19, 4,650 × 75 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 45; private; medical: unknown; seat: center; flight hours: 42 total, 14 as pilot in command

## Weather

- Conditions: Visual (VMC), Dawn
- Visibility: 30 statute miles
- Lowest ceiling: none
- Temperature: 79 °F, dew point 39 °F
- Altimeter: 30.00 inHg
- Observed at: TRK, 1 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 19930817029609A](https://openairdocs.org/incident/19930817029609A), Aug 17, 1993: Pilats B4PC11AF, Truckee, CA, Substantial damage. Erractic flight seen of glider under aircraft tow. Pilot tried turn back lost control. Tow cable frayed and binding

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.