# NTSB MIA92LA153: Burkhart Grob G103, N2135R, Knoxville, TN, July 25, 1992

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: July 25, 1992, 15:12 local (19:12 UTC)
- Place: Knoxville, TN
- Coordinates: 35.980953, -83.800048 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=35.9810&lon=-83.8000&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious, 1 uninjured
- Status: Completed, report August 31, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 33113
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA92LA153
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/33113/pdf
- Page: https://openairdocs.org/ntsb/MIA92LA153

## Probable cause

THE PILOT-IN-COMMAND'S FAILURE TO PROPERLY INSTRUCT THE PASSENGER ON AIRCRAFT CONTROLS PRIOR TO TAKEOFF, RESULTING IN THE PASSENGER INADVERTENTLY RELEASING THE TOW CABLE AS THE GLIDER WAS BEING TOWED THROUGH 150 FEET.

## Sequence of events

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

- Miscellaneous/other, takeoff - initial climb
  - passenger briefing - inadequate, pilot in command (cause)
  - glider/tow release - inadvertent use, passenger (cause)
- Forced landing, descent
- On ground/water encounter with terrain/water, landing
  - terrain condition - high vegetation
- On ground/water collision with object, landing

## Analysis

SHORTLY AFTER TAKEOFF, PILOT WAS ATTEMPTING TO INSTRUCT REAR SEAT PASSENGER, WHO DID NOT SPEAK ENGLISH, HOW TO OPEN AIR VENT. THE PASSENGER INADVERTENTLY PULLED THE TOW CABLE RELEASE AND THE GLIDER DISCONNECTED FROM THE TOW AIRCRAFT AT 150 FEET. THE PILOT ATTEMPTED TO TURN BACK TO THE AIRPORT, BUT WAS UNABLE TO MAKE THE RUNWAY BEFORE LANDING ON A GRASSY SLOPE, AND GROUND LOOPING, AT WHICH TIME THE AIRCRAFT COLLIDED WITH TREES.

## Aircraft

- Registration: [N2135R](https://openairdocs.org/deregistered/N2135R-1994-07-18), registration cancelled 1994-07-18, S/N 3601 (OpenAirDocs)
- Reported make and model: BURKHART GROB G103
- Registry model: [Burkhart Grob Flugzeugbau G103 TWIN ASTIR](https://openairdocs.org/model/burkhart-grob-flugzeugbau-g103-twin-astir) (registry code 1660202) (OpenAirDocs)
- Category: Glider
- Serial number: 3601
- Airframe hours: 1020
- Engines: unknown
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Robert L. Davis, doing business as Smokey Mountain Soaring Assoc.
- Registered owner: Robert L. Davis
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, November 1, 1991, 60 hours before
- Departed: DKX
- Airport: DKX, Downtown Island Airport, runway 26, 3,500 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 41; private; medical: unknown, unknown; seat: front; flight hours: 733 total, 3 in this make and model, 720 as pilot in command, 12 in the last 90 days, 2 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 300° at 3 knots
- Visibility: 10 statute miles
- Lowest ceiling: 12,000 ft broken
- Temperature: 86 °F, dew point 77 °F
- Altimeter: 30.00 inHg
- Observed at: TYS, 5 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 19920725027299A](https://openairdocs.org/incident/19920725027299A), Jul 25, 1992: Grob G103ATWINII, Knoxville, TN, Substantial damage. Passenger inadvertently pulled tow release while being towed at 150 ft AGL. Unable return. Landed off airport.

## Other investigations on N2135R (1)

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.

- [NTSB ATL86LA164](https://openairdocs.org/ntsb/ATL86LA164), Jun 8, 1986: Burkhart Grob G103 (N2135R), Benton, TN, substantial damage

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.