SEA94LA210

NTSB accident investigation · Burkhart Grob G-109B · Rock Springs, WY · August 14, 1994

Accident · Serious injuriesLimited investigationFinal report
Date
August 14, 1994, 13:23 local (19:23 UTC)
Place
Rock Springs, WY
Injuries
1 serious
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N45GFBurkhart Grob G-109B
Weather
Visual (VMC) · Day
Status
Completed · report June 19, 1995
Report
Approved by Office Director
FAA report
19940814032209A
Case key
41997

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

Aircraft control was not maintained. Factors to the accident were: high density altitude and wind gusts.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

In flight collision with terrain/waterTakeoff - initial climb
Weather condition - high density altitudeFactor
Aircraft control - not maintainedPilot in commandCause
Weather condition - gustsFactor
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
Reported as
Burkhart Grob G-109B
Category
Glider
Serial number
6345
Engine
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

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
71
Certificate
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.