# NTSB FTW95LA335: Schempp-Hirth Ventus A, N307L, Rocksprings, TX, August 7, 1995

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: August 7, 1995, 17:30 local (22:30 UTC)
- Place: Rocksprings, TX
- Coordinates: 30.009418, -100.209106 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=30.0094&lon=-100.2091&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed, report September 3, 1996
- Report: Approved by Office Director
- NTSB case key (mKey): 19531
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW95LA335
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/19531/pdf
- Page: https://openairdocs.org/ntsb/FTW95LA335

## Probable cause

DEBONDING OF MYLAR TAPE THAT WAS USED TO SEAL A GAP ON THE ELEVATOR, WHICH RESULTED IN INADEQUATE ELEVATOR CONTROL AUTHORITY.

## Sequence of events

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

- Airframe/component/system failure/malfunction, cruise
  - flight control,elevator surface - debonded (cause)
  - flt control syst,elevator control - inadequate (cause)
  - bail-out/emergency ejection - performed, pilot in command
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

ACCORDING TO THE PILOT, AS HE ATTEMPTED TO ACCELERATE TO GLIDE SPEED, HE EXPERIENCED PROBLEMS WITH ELEVATOR CONTROL. HE SAID HE HAD TO APPLY FULL ELEVATOR BEFORE THE GLIDER WOULD RESPOND TO THE CONTROL INPUTS AND THAT IT RESPONDED VERY SLOWLY.'  THE PILOT WAS GOING TO LAND ON A RANCH ROAD; HOWEVER, BECAUSE OF THE CONTROL PROBLEM, HE DETERMINED IT WAS SAFER TO BAIL OUT.  THE GLIDER IMPACTED THE GROUND IN A LEVEL ATTITUDE, DAMAGING THE FUSELAGE, HORIZONTAL STABILIZER, AND CANOPY. EXAMINATION OF THE GLIDER REVEALED THAT MYLAR TAPE, WHICH WAS USED AS A GAP SEAL FOR THE ELEVATOR, HAD PARTIALLY SEPARATED.

## Factual narrative

On August 7, 1995, at 1730 central daylight time, a Schempp-Hirth Ventus A, N307L, was substantially damaged following a loss of control near Rocksprings, Texas.  The airline transport rated pilot received minor injuries.  The glider was being operated as a personal flight under Title 14 CFR Part 91.  The flight originated in Uvalde, Texas, at 1345.  Visual meteorological conditions prevailed, and a flight plan was not filed for the round robin flight.

During a telephone interview with the investigator-in-charge the pilot reported that when he attempted to accelerate to glide airspeed he experienced problems with elevator control.  He had to apply full elevator before the glider would respond to control inputs.  It also responded "very slowly" to the elevator control inputs.  The pilot further reported he was going to land on a ranch road; however, because of the control problem he elected to bail out.  The glider impacted the ground in a level attitude damaging the fuselage, horizontal stabilizer, and canopy.

Examination of the glider by a Federal Aviation Administration inspector revealed that the Mylar tape, which was used as a gap seal for the elevator, had partially separated.

## Aircraft

- Registration: [N307L](https://openairdocs.org/deregistered/N307L-1997-02-03), registration cancelled 1997-02-03, S/N 38 (OpenAirDocs)
- Reported make and model: SCHEMPP-HIRTH VENTUS A
- Registry model: [Schempp-Hirth K G VENTUS A](https://openairdocs.org/model/schempp-hirth-k-g-ventus-a) (registry code 3802050) (OpenAirDocs)
- Category: Glider
- Serial number: 38
- Airframe hours: 1425
- Engines: unknown
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Fredrick G. Voltz
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Annual, April 11, 1995, 30 hours before
- Departed: UVA, UVLADE, TX

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 33; flight engineer, flight instructor, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: center; flight hours: 6,322 total, 131 in this make and model, 2,500 as pilot in command, 210 in the last 90 days, 70 in the last 30 days, 13 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 35 statute miles
- Lowest ceiling: none
- Temperature: 100 °F

## 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 19950807023699A](https://openairdocs.org/incident/19950807023699A), Aug 7, 1995: Sphrth VENTUSA, Rocksprings, TX, Substantial damage. Unable accelerate glide speed and elevator problem. Bailed out. Mylar gap seal tape came loose on elevator.

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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