LAX98LA233

NTSB accident investigation · Air Tractor AT-400 · Tranquillity, CA · July 17, 1998

Accident · No injuriesLimited investigationFinal report
Date
July 16, 1998, 22:05 local (Jul 17, 1998, 05:05 UTC)
Place
Tranquillity, CA
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N2373VAir Tractor AT-400
Weather
Visual (VMC) · Night/dark
Status
Completed · report June 22, 2000
Report
Approved by Office Director
FAA report
19980716021219A
Case key
43189

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 detect and avoid a set of wires during a night aerial application flight. Factors in the accident were the pilot's failure to perform an adequate preflight inspection of the field to determine obstruction locations and the dark night lighting conditions.

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,transmission
Light condition - dark nightFactor
Preflight planning/preparation - inadequatePilot in commandCause
Visual/aural detectionPilot in command
Visual lookout - restrictedPilot in command
Clearance - inadequatePilot in commandCause

Analysis

The pilot said that this was the first flight at a new field, and he had not visually inspected the field before spraying it. He made a pass over the field to check for wires, and did not see any. On the second pass he saw a steel power cable strung between poles that was in his flight path. The pilot stated that it was too late to pull up to avoid the cable, and he pushed the nose of the aircraft down to fly underneath it. The aircraft, equipped with a wire deflector, struck a telephone wire underneath the initial steel cable. The wire deflector and the vertical stabilizer separated from the aircraft. The pilot began to lose directional and roll control, and he pushed the nose towards the ground and made a forced landing. The pilot stated that there were no mechanical malfunctions with the engine or flight controls prior to striking the wires. The night was dark with no moon.

Factual narrative

On July 16, 1998, at 2205 hours Pacific daylight time, an Air Tractor AT-400, N2373V, struck a telephone wire and made a forced landing in a tomato field near Tranquillity, California. The aircraft, operated by Western AG Aviation under 14 CFR Part 137, was on an aerial application flight and sustained substantial damage. The commercial pilot was not injured. Visual meteorological conditions existed for the night flight and no flight plan was filed.

The pilot stated that this was the first flight at this field, and that he had not visually checked the field before going to spray it. He stated that he had made one pass from the north to the south to check for wires, and did not see any. On his second pass, he saw the steel cable strung between poles, but he was flying right into it and believed it was too late to pull up, so he pushed the nose of the aircraft down to fly underneath the wire. The aircraft was equipped with a wire deflector that hit a telephone wire underlying the steel cable. The pilot stated that the wire deflector broke, as well as the vertical stabilizer. The aircraft started to rotate to the left, as if it were going to roll over, and to stop that from happening he "pushed the nose into the ground," and landed immediately.

In an interview with a Federal Aviation Administration inspector from the Fresno, California, Flight Standards District Office, the pilot reported that he flew under a power line, but did not see that there was a telephone line approximately 3-4 feet lower. The rudder of the aircraft struck the telephone line and he made a forced landing. The pilot did not note any mechanical malfunctions with the engine. The night was dark with no moon.

Aircraft

Registration
N2373V
Reported as
Air Tractor AT-400
Category
Airplane
Serial number
400-0426
Airframe hours
8,189
Engine
P&W PT-6A-15AG, 680 horsepower, turbo prop
Damage
Substantial damage
Flight
Aerial application · Part 137
Registered owner
Western Ag. Aviation Inc.
Airworthiness certificate
Special, Restricted (Special)
Last inspection
100 hour · July 2, 1998 · 762 hours before
Departed
Tranquility, CA

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
61
Certificate
Commercial
Airplane ratings
Single-engine land
Medical
Class 2, Valid Medical--w/ waivers/lim
Seat
Center
Flight hours
20,000 total · 8,000 in this make and model · 20,000 as pilot in command · 200 in the last 90 days · 70 in the last 30 days · 2 in the last 24 hours

Weather

Conditions
Visual (VMC) · Night/dark
Wind
320° at 6 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
79 °F, dew point 63 °F
Observed at
NLC, 25 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.