# NTSB SEA94LA210: Burkhart Grob G-109B, N45GF, Rock Springs, WY, August 14, 1994 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: August 14, 1994, 13:23 local (19:23 UTC) - Place: Rock Springs, WY - Location: 41.5942° N, 109.0652° W: Placed by OpenAirDocs at SOUTHWEST WYOMING RGNL (RKS), within about a mile (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=41.5942&lon=-109.0652&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 June 19, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 41997 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA94LA210 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41997/pdf - Page: https://openairdocs.org/ntsb/SEA94LA210 ## Probable cause AIRCRAFT CONTROL WAS NOT MAINTAINED. FACTORS TO THE ACCIDENT WERE: HIGH DENSITY ALTITUDE AND WIND GUSTS. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with terrain/water, takeoff - initial climb - weather condition - high density altitude (contributing factor) - aircraft control - not maintained, pilot in command (cause) - weather condition - gusts (contributing factor) - terrain condition - high vegetation ## Analysis SHORTLY AFTER TAKEOFF IN GUSTING WINDS AND HIGH DENSITY ALTITUDE, THE MOTORIZED GLIDER DRIFTED OFF TO THE LEFT SIDE OF THE RUNWAY AND COLLIDED WITH SAGE BRUSH. THE PILOT CORRECTED WITH RIGHT RUDDER; HOWEVER, THE GLIDER DRIFTED BACK OVER, AND OFF TO THE RIGHT SIDE OF THE RUNWAY. THE GLIDER DID NOT GAIN SUFFICIENT ALTITUDE TO CLEAR THE SAGE BRUSH AND SUBSEQUENTLY COLLIDED WITH THE TERRAIN. THE PILOT REPORTED NO MECHANICAL FAILURES OR MALFUNCTIONS WITH THE GLIDER AT THE TIME OF THE ACCIDENT. ## Factual narrative On August 14, 1994, at 1323 hours mountain daylight time (MDT), a Grob G-109B motorized glider, N45GF, recently purchased and being flown by Bonny L. Feather, a private pilot, was substantially damaged during collision with terrain during takeoff from runway 9 at the Rock Springs Municipal Airport, Rock Springs, Wyoming. The pilot received serious injuries. Visual meteorological conditions existed with gusting winds and no flight plan was filed. The flight, which was personal in nature, was to have been conducted in accordance with 14CFR91, and was destined for Cheyenne, Wyoming. In a written statement, the pilot reported that the takeoff roll was normal and directional control was easily maintained. The tail wheel lifted off at 24 to 26 knots and the glider weather cocked to the left. The pilot countered with right rudder control and left wing down. The glider lifted off and began drifting to the left side of the runway at approximately three feet above ground level. The pilot stated that the glider may have touched sage brush before drifting back over the runway and to the right side. The glider then collided with the sage brush and subsequently the ground. A witness at the airport stated that it appeared that the glider was having difficulty gaining altitude after takeoff from runway 9. The witness observed the glider make one complete 360 degree left turn and then start another turn before he saw it collide with the terrain. The witness stated that he did not notice any "dust devils" or unusual wind conditions at the time of the accident. The witness did note the weather conditions and reported the winds from 30 degrees at ten knots, gusting to 17. The temperature was 81 degrees, and atmospheric pressure was 30.40" Hg. Density altitude was calculated at 9,180 feet. The pilot reported that there were no mechanical failures or malfunctions with the glider at the time of the accident. ## Aircraft - Registration: [N45GF](https://openairdocs.org/aircraft/N45GF), registered now, S/N 6345 (OpenAirDocs) - Reported make and model: Burkhart Grob G-109B - Registry model: [Burkhart Grob G-109B](https://openairdocs.org/model/burkhart-grob-g-109b) (registry code 1660205) (OpenAirDocs) - Category: Glider - Serial number: 6345 - Engines: GROB 2500E1 90 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Feather, Bonny L. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 15, 1994 - Destination: CYS, CHEYENNE, WY - Airport: RKS, Rock Springs, runway 9, 10,000 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 71; private; airplane ratings: single-engine land; medical: class 3, expired; seat: left; flight hours: 1,108 total, 62 in this make and model, 4 in the last 90 days, 4 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 30° at 10 knots, gusting 17 - Visibility: 60 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 30 °F - Altimeter: 30.00 inHg - Observed at: RKS ## 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 19940814032209A](https://openairdocs.org/incident/19940814032209A), Aug 14, 1994: Grob G109B, Rock Springs, WY, Substantial damage. Motorized glider recent purchased drifted off runway on takeoff. Made 360 to regain runway then impacted sage brush 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.