LAX03LA198

NTSB accident investigation · Kowtun Mini 500 · Phoenix, AZ · June 14, 2003

Accident · No injuriesLimited investigationFinal report
Date
June 13, 2003, 20:20 local (Jun 14, 2003, 03:20 UTC)
Place
Phoenix, AZ
Injuries
1 uninjured
Damage
Destroyed
Phase of flight
Maneuvering
Aircraft
N919WKKowtun Mini 500
Weather
Visual (VMC) · Night
Status
Completed · report September 29, 2004
Report
Approved by Office Director
Parties
Federal Aviation Administration
FAA report
20030613012719A
Case key
57241

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 pilot's failure to maintain directional control of the helicopter.

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 flightHover - in ground effect
Directional control - not maintainedPilot in commandCause
Roll overHover - in ground effect
Terrain condition - open field

Analysis

The helicopter experienced a loss of directional control while hovering, collided with the ground, and rolled over. The pilot was performing a hover taxi test flight after adjusting the carburetor. The pilot said in a written report that shortly into the flight, the helicopter "started to spin to the right and would not respond to the left pedal." It then impacted the ground, rolled on its right side, and was consumed by fire. In the section of NTSB Form 6120.1/2, which asks if there was a mechanical malfunction or failure, the pilot wrote "tail rotor drive shaft failure." When contacted by a Safety Board investigator for clarification of the tail rotor issue, the pilot declined to answer any questions pertaining to the accident.

Factual narrative

On June 13, 2003, about 2020 mountain standard time, an experimental Kowtun Mini 500 helicopter, N919WK, experienced a loss of directional control, collided with the ground, and rolled over at Phoenix Deer Valley Airport (DVT), Phoenix, Arizona. The pilot/owner was operating the helicopter under the provisions of 14 CFR Part 91. The pilot, the sole occupant, was not injured. The helicopter was destroyed. Night visual meteorological conditions prevailed, and no flight plan had been filed. The primary wreckage was at 33 degrees 41.17 minutes north latitude and 112 degrees 4.17 minutes west longitude.

In a written statement, the pilot reported that he had just "tweaked" the carburetor and was performing a hover taxi test flight when the helicopter "started to spin to the right and would not respond to the left pedal." It then impacted the ground, rolled on its right side, and was consumed by fire. In the section of NTSB Form 6120.1/2, which asks if there was a mechanical malfunction or failure, the pilot wrote "tail rotor drive shaft failure."

A Safety Board investigator contacted the pilot on July 21, 2003, to learn more about the tail rotor drive shaft issue. The pilot, however, stated that the Federal Aviation Administration was trying to revoke his license and would not answer any questions pertaining to the accident. He then referred the investigator to his lawyer. Subsequent attempts to gain further information from the pilot or his attorney were unsuccessful.

Aircraft

Registration
N919WK
Reported as
Kowtun Mini 500
Category
Helicopter, amateur-built
Serial number
413
Airframe hours
50
Engine
Bombardier Mini 500A, 67 horsepower, reciprocating
Damage
Destroyed
Fire
On-Ground
Flight
Personal · Part 91
Registered owner
Walter Kowtun
Airworthiness certificate
Special, Experimental (Special)
Last inspection
AAIP · June 7, 2003 · 45 hours before
Departed
KDVT · Deer Valley, AZ
Airport
DVT · Phoenix Deer Valley Airport

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
47
Injuries
None
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, Valid Medical--no waivers/lim.
Last flight review
July 31, 2001
Seat
Single
Flight hours
700 total

Weather

Conditions
Visual (VMC) · Night
Wind
230° at 5 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
91 °F, dew point 39 °F
Altimeter
29.78 inHg
Observed at
KDVT, 1 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.