# NTSB FTW91FA131: Schempp-Hirth DISCUS-B, Medina, TX, July 31, 1991

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: July 31, 1991, 15:00 local (20:00 UTC)
- Place: Medina, TX
- Coordinates: 29.799667, -99.250953 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=29.7997&lon=-99.2510&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal, 1 minor
- Status: Completed, report March 9, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 23271
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW91FA131
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/23271/pdf
- Page: https://openairdocs.org/ntsb/FTW91FA131

## Probable cause (aircraft 2)

THE FAILURE OF THE PILOT IN COMMAND TO MAINTAIN AN ADEQUATE VISUAL LOOKOUT. A FACTOR WAS COLLISION INDUCED INCAPACITATION.

## Probable cause (aircraft 1)

THE FAILURE OF THE OTHER PILOT TO MAINTAIN AN ADEQUATE VISUAL LOOKOUT.

## Sequence of events

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

- Midair collision, maneuvering
  - visual lookout - not maintained, pilot of other aircraft (cause)
- Loss of control - in flight, maneuvering
  - aircraft control - not possible, pilot in command
- In flight collision with terrain/water, descent - uncontrolled
- Midair collision, maneuvering
  - visual lookout - not maintained, pilot in command (cause)
- Loss of control - in flight, maneuvering
  - incapacitation, pilot in command (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis (aircraft 2)

THE GLIDERS COLLIDED AT APPROXIMATELY 6,000 FEET MSL WHILE CLIMBING IN A THERMAL AREA. IN THIS PARTICULAR AREA, APPROXIMATELY 20 GLIDERS WERE MANEUVERING ATTEMPTING TO ATTAIN OPTIMUM LIFT. THIS RESULTED IN OVERLAPPING FLIGHT PATHS. THE PILOT OF JAPANESE REGISTRY JA2413 OBSERVED FINNISH REGISTRY OH825 AND TWO OTHER GLIDERS APPROACHING FROM HIS LEFT AND BELOW HIS ALTITUDE. HE LOST SIGHT OF THE GLIDERS AND SHORTLY THEREAFTER OH825 STRUCK HIS AFT FUSELAGE ON THE LEFT SIDE, RESULTING IN THE SEPARATION OF HIS EMPENNAGE. PAINT TRANSFERS FROM THE RIGHT SIDE CANOPY TRACK AREA OF OH825 WERE FOUND ON THE LEFT SIDE OF JA2413 AT THE 7 O'CLOCK POSITION WHEN VIEWING JA2413 ALONG ITS LONGITUDINAL AXIS FROM THE REAR. ADDITIONAL PAINT TRANSFERS WERE LOCATED AT THE 8 O'CLOCK, 9 O'CLOCK AND 10 O'CLOCK POSITIONS. OH825 CONTINUED GLIDING, BUT IN AN ERRATIC MANNER, EVENTUALLY COLLIDING WITH THE TERRAIN. THE COCKPIT AREA OF OH825 SUSTAINED IN-FLIGHT COLLISION DAMAGE. THE PILOT OF JA2413 PARACHUTED TO SAFETY.

## Analysis (aircraft 1)

THE GLIDERS COLLIDED AT APPROXIMATELY 6,000 FEET MSL WHILE CLIMBING IN A THERMAL AREA. IN THIS PARTICULAR AREA, APPROXIMATELY 20 GLIDERS WERE MANEUVERING ATTEMPTING TO ATTAIN OPTIMUM LIFT. THIS RESULTED IN OVERLAPPING FLIGHT PATHS. THE PILOT OF JAPANESE REGISTRY JA2413 OBSERVED FINNISH REGISTRY OH825 AND TWO OTHER GLIDERS APPROACHING FROM HIS LEFT AND BELOW HIS ALTITUDE. HE LOST SIGHT OF THE GLIDERS. SHORTLY THEREAFTER, OH825 STRUCK HIS AFT FUSELAGE ON THE LEFT SIDE, WHICH RESULTED IN THE SEPARATION OF HIS EMPENNAGE. PAINT TRANSFER FROM THE RIGHT SIDE CANOPY TRACK AREA OF OH825 WAS FOUND ON THE LEFT SIDE OF JA2413 AT THE 7 O'CLOCK POSITION WHEN VIEWING JA2413 ALONG ITS LONGITUDINAL AXIS FROM THE REAR. ADDITIONAL PAINT TRANSFERS WERE LOCATED AT THE 8 O'CLOCK, 9 O'CLOCK AND 10 O'CLOCK POSITIONS. OH825 CONTINUED GLIDING, BUT IN AN ERRATIC MANNER, EVENTUALLY COLLIDING WITH THE TERRAIN. THE COCKPIT AREA OF OH825 SUSTAINED THE IN-FLIGHT COLLISION DAMAGE. THE PILOT OF JA2413 PARACHUTED TO SAFETY.

## Aircraft 1

- Registration: JA241 (not matched to a registry record)
- Reported make and model: SCHEMPP-HIRTH DISCUS-B
- Category: Glider
- Serial number: 240
- Engines: unknown
- Damage: Destroyed
- Flight: Personal, Part 91
- Operator: Atsushi Kodama
- Registered owner: Atsushi Kodama
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, November 17, 1990
- Departed: UVA, UVALDE, TX

## Aircraft 2

- Registration: OH825 (not matched to a registry record)
- Reported make and model: PZL-Mielec 55-1
- Category: Glider
- Serial number: 551190002
- Airframe hours: 202
- Engines: unknown
- Damage: Destroyed
- Flight: Personal, Part 91
- Operator: Llmasotaboulun Lentokerhary
- Registered owner: Llmasotaboulun Lentokerhary
- Airworthiness certificate: Standard, Normal
- Last inspection: Continuous airworthiness, April 5, 1990
- Departed: UVA, UVALDE, TX

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot, aircraft 1; age 45; commercial; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, unknown; seat: center; flight hours: 10,000 total, 650 in this make and model
- Pilot, aircraft 2; age 25; private; medical: unknown, unknown; seat: center; toxicology performed; flight hours: 1,000 total, 700 in this make and model, 80 in the last 90 days, 30 in the last 30 days, 5 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 90° at 10 knots
- Visibility: 20 statute miles
- Lowest ceiling: none
- Temperature: 95 °F, dew point -0 °F

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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