SEA00LA151

NTSB accident investigation · Kokenge Glastar · Butte, MT · August 2, 2000

Accident · Serious injuriesLimited investigationFinal report
Date
August 2, 2000, 10:20 local (16:20 UTC)
Place
Butte, MT
Injuries
2 serious
Damage
Destroyed
Phase of flight
Initial climb
Aircraft
N4350KKokenge Glastar
Weather
Visual (VMC) · Day
Status
Completed · report July 2, 2001
Report
Approved by Office Director
FAA report
20000802010159A
Case key
49880

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

The NTSB’s determination of the probable cause, and any contributing factors.

A loss of aircraft control for undetermined reasons.

Analysis

Witnesses reported that they observed the airplane begin its takeoff roll on runway 33 from taxiway E. They stated that after becoming airborne, the airplane got about 50 to 60 feet in the air, then made a sharp right turn. The witnesses stated that the airplane '[took] a nosedive' or 'nosed into the ground' when it made this sharp right turn. The aircraft impacted the ground and came to rest just east of the intersection of runways 15/33 and 11/29. A post-crash fire ensued; however, the aircraft occupants were moved to safety by responding emergency personnel. The pilot reported to the NTSB that he had little recollection of the accident sequence. Investigators did not determine the reason for the sharp right turn and nose drop to ground impact observed by the witnesses. A report by the responding FAA inspector stated that the aircraft's engine was producing power at impact.

Factual narrative

On August 2, 2000, approximately 1020 mountain daylight time, a Kokenge Glastar experimental-category airplane, N4350K, was destroyed in a collision with terrain following takeoff from runway 33 at Bert Mooney Field, Butte, Montana. The private pilot-in-command and his passenger received serious injuries in the accident. Visual meteorological conditions prevailed, and the FAA did not indicate any record of the aircraft filing a flight plan for the 14 CFR 91 personal flight bound for Yakima, Washington.

Witnesses reported that they observed the airplane begin its takeoff roll on runway 33 from taxiway E. They stated that after becoming airborne, the airplane got about 50 to 60 feet in the air, then made a sharp right turn. The witnesses stated that the airplane "[took] a nosedive" or "nosed into the ground" when it made this sharp right turn. The aircraft impacted the ground and came to rest just east of the intersection of runways 15/33 and 11/29. A post-crash fire ensued; however, the aircraft occupants were moved to safety by responding emergency personnel. The pilot reported to the NTSB that he had little recollection of the accident sequence. Investigators did not determine the reason for the sharp right turn and nose drop to ground impact observed by the witnesses. A report by the responding FAA inspector, from the Helena, Montana Flight Standards District Office (FSDO), stated that the aircraft's engine was producing power at impact.

According to one witness, an airport weather observer who had just taken an hourly observation, the weather conditions at the time of the accident were: temperature 79 degrees F, winds variable at 5 knots, few clouds at 10,000 feet, few clouds at 15,000 feet, and visibility 25 statute miles with haze. Based on a pressure altitude equal to Mooney Field's elevation of 5,545 feet above sea level and temperature of 79 degrees F, density altitude at the time was computed to be approximately 8,000 feet.

According to U.S. Government flight information publications, runway 33 is a 9,000 foot long by 150 foot wide grooved asphalt runway. Approximately 7,070 feet are available for an intersection takeoff from taxiway E.

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.

Loss of control - in flightTakeoff - initial climb
Reason for occurrence undeterminedCause
Weather condition - high density altitude
In flight collision with terrain/waterDescent - uncontrolled

Aircraft

Registration
N4350K
Reported as
Kokenge Glastar
Category
Airplane, amateur-built
Serial number
5006
Airframe hours
106
Engine
Lom XM332B, 160 horsepower, reciprocating
Damage
Destroyed
Fire
On-Ground
Flight
Personal · Part 91
Registered owner
Roy F. Kokenge
Airworthiness certificate
Special, Experimental (Special)
Last inspection
Unknown · June 8, 2000 · 59 hours before
Departed
BTM
Destination
YKM · Yakima, WA
Airport
BTM · Bert Mooney, runway 33, 9,000 × 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
66
Certificate
Private
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 3, Valid Medical--w/ waivers/lim
Seat
Left
Flight hours
809 total · 106 in this make and model · 605 as pilot in command · 81 in the last 90 days · 37 in the last 30 days · 13 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
Variable at 5 knots
Visibility
25 statute miles
Lowest ceiling
None
Temperature
79 °F

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.