# NTSB FTW91LA114: Schempp-Hirth Ventus CM, N9999R, Marfa, TX, July 2, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 2, 1991, 14:00 local (19:00 UTC)
- Place: Marfa, TX
- Coordinates: 30.309707, -104.020523 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=30.3097&lon=-104.0205&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report March 31, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 23359
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW91LA114
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/23359/pdf
- Page: https://openairdocs.org/ntsb/FTW91LA114

## Probable cause

THE PILOT MISJUDGED THE APPROACH.  FACTORS WERE THE HIGH DENSITY ALTITUDE, THE DOWNDRAFT, AND THE DTERIORTED CLIMB PERFORMANCE.

## Sequence of events

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

- In flight encounter with weather, takeoff - initial climb
  - weather condition - high density altitude (contributing factor)
  - weather condition - downdraft (contributing factor)
  - aircraft performance,climb capability - deteriorated (contributing factor)
- In flight collision with object, landing - flare/touchdown
  - object - fence
  - object - fence post
  - planned approach - misjudged, pilot in command (cause)

## Analysis

THE PILOT OF THE MOTORIZED GILDER ENCOUNTERED A DOWNDRAFT FROM CONVECTIVE ACTIVITY DURING INITIAL CLIMB OUT FROM THE RUNWAY.  THE GILDER WAS CLIMBING AT 150 TO 200 FEET PER MINUTE WAS 100 ABOVE GROUND WHEN IT STARTED TO DESCEND AT 200 FEET PER MINUTE. THE PILOT ATTEMPTED A LANDING IN AN OPEN FIELD, BUT STRUCK A FENCE DURING THE APPROACH. THE GLIDER WAS POWERED BY A TWO STROKE 25HP ENGINE AND WAS OPERATING WITH FULL WATER BALLAST AT MAXIMUM GROSS WEIGHT. THE DENSITY ALTITUDE WS ESTIMATED TO BE 9,000 FEET WHEN THE ACCIDENT OCCURRED. THE PILOT WAS A COMPETITOR IN THE NATIONAL MOTOR GLIDER COMPETITION.

## Aircraft

- Registration: [N9999R](https://openairdocs.org/deregistered/N9999R-2006-05-25), registration cancelled 2006-05-25, S/N 36, built 1990 (OpenAirDocs)
- Reported make and model: SCHEMPP-HIRTH VENTUS CM
- Registry model: [Schempp-Hirth VENTUS CM](https://openairdocs.org/model/schempp-hirth-ventus-cm) (registry code 3800266) (OpenAirDocs)
- Registry engine: [Solo 2350 series](https://openairdocs.org/engine/solo-2350-series) (registry code 58107, 2 cycle) (OpenAirDocs)
- Category: Glider
- Serial number: 36
- Engines: SOLO 235B 25 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Rogar N. Buchanan
- Registered owner: Rogar N. Buchanan
- Airport: MRF, Marfa Municipal, runway 21, 5,300 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 50; commercial; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; flight hours: 1,500 total, 200 in this make and model, 1,440 as pilot in command, 12 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 300° at 3 knots
- Visibility: 30 statute miles
- Lowest ceiling: none
- Temperature: 88 °F, dew point 57 °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 19910702025589A](https://openairdocs.org/incident/19910702025589A), Jul 2, 1991: Sphrth VENTUSA, Marfa, TX, Substantial damage. Lost lift on motorized launch,struck a fence and impacted sideways. Density altitude and downdraft plus low power.

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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