FTW97LA019

NTSB accident investigation · Air Tractor AT-502 · Throckmorton, TX · October 18, 1996

Accident · Serious injuriesLimited investigationFinal report
Date
October 18, 1996, 18:30 local (23:30 UTC)
Place
Throckmorton, TX
Injuries
1 serious
Damage
Destroyed
Phase of flight
Maneuvering
Aircraft
N4549ZAir Tractor AT-502
Weather
Visual (VMC) · Day
Status
Completed · report September 30, 1997
Report
Approved by Office Director
Case key
20095

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

failure of the pilot to maintain clearance of a transmission wire during pullup from a swath run. The proximity of the transmission wire was a related factor. The installation of wire cutter equipment on the landing gear might have prevented or reduced the level of damage or injury.

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 objectManeuvering - aerial application
Object - wire,transmissionFactor
Clearance - not maintainedPilot in commandCause
Misc eqpt/furnishings - not installed
In flight collision with terrain/waterDescent - uncontrolled

Analysis

The pilot reported that he made an aerial application swath run in a north to south direction. During pull-up from the swath run, the airplane's main landing gear (which were not equipped with wire cutters) caught on an east to west oriented unmarked electrical transmission wire. The pilot further stated that 'the east end of the wire became entangled in the airplane's rudder horn, forcing the airplane into an uncontrolled left turn.' The engine power and the momentum of the airplane were sufficient to 'snap three telephone poles.' Subsequently, the airplane impacted the ground and came to rest inverted. A postimpact fire destroyed the airplane.

Factual narrative

On October 18, 1996, approximately 1830 central daylight time, an Air Tractor AT-502, N4549Z, was destroyed after a wire strike while maneuvering near Throckmorton, Texas. The commercial pilot, sole occupant in the airplane, was seriously injured. The airplane was registered to and operated by New Nueces Ag Service Inc., under Title 14 CFR Part 137. Visual meteorological conditions prevailed for the aerial application flight which originated from Olney, Texas, approximately 59 minutes before the accident. A flight plan was not filed for the local flight.

The pilot reported to the investigator-in-charge that he was flying an application swath in a north to south direction. On the pull-up, the airplane's main landing gear (which were not equipped with wire cutters) caught on an east to west oriented unmarked electrical transmission wire. The pilot further stated that "the east end of the wire became entangled in the airplane's rudder horn, forcing the airplane into an uncontrolled left turn." The engine power and the momentum of the airplane were sufficient to "snap three telephone poles." Subsequently the airplane impacted the ground, and came to rest inverted. A post impact fire destroyed the aircraft.

Aircraft

Registration
N4549Z
Reported as
Air Tractor AT-502
Category
Airplane
Serial number
502-0129
Engine
P&W PTGA-15AG, 680 horsepower, turbo prop
Damage
Destroyed
Fire
On-Ground
Flight
Aerial application · Part 137
Registered owner
New Nueces Ag Service, Inc.
Airworthiness certificate
Special, Restricted (Special)
Departed
ONY · Olney, TX

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
48
Certificate
Commercial
Airplane ratings
Multi-engine land, Single-engine land
Medical
Class 2, Valid Medical--w/ waivers/lim
Seat
Front
Flight hours
18,219 total · 4,246 in this make and model · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
360° at 5 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
75 °F