CHI97LA124

NTSB accident investigation · Air Tractor AT-301 · Huron, SD · May 7, 1997

Accident · No injuriesLimited investigationFinal report
Date
May 7, 1997, 11:12 local (16:12 UTC)
Place
Huron, SD
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N23640Air Tractor AT-301
Weather
Visual (VMC) · Day
Status
Completed · report September 5, 1997
Report
Approved by Office Director
FAA report
19970507008419A
Case key
10559

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 clearance from known transmission lines.

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
Clearance - not maintainedPilot in commandCause
Object - wire,transmission
In flight collision with terrain/waterDescent - uncontrolled

Analysis

The pilot said that he had completed his turn to enter the field he was spraying. He entered the field downwind over the trees. On entering the field the airplane struck power transmission cables. The airplane impacted on the ground and came to rest in a wheat field. Examination of the wreckage showed part of a transmission line wrapped around the propeller.

Factual narrative

On May 7, 1997, at 1112 central daylight time (cdt), an Air Tractor, AT-301, N23640, operated by a commercial pilot, sustained substantial damage when during maneuvering the airplane struck some high-tension power lines. The airplane subsequently impacted the terrain, 12 miles north of Huron, South Dakota. Visual meteorological conditions prevailed at the time of the accident. The aerial application flight was being conducted under 14 CFR Part 137. A flight plan was not on file. The pilot reported no injuries. The local flight originated at Huron, South Dakota, at 1045 cdt.

In his written statement, the pilot said that he had completed his turn to enter the field he was spraying. He entered the field down wind over the trees. On entering the field the airplane struck power transmission cables. The airplane impacted on the ground and came to rest in a wheat field.

The Federal Aviation Administration (FAA) inspector who examined the wreckage at the scene found the airplane resting in a wheat field on its left side, approximately 400 feet northeast of a support tower for some east-west running transmission lines. Several ground impact marks were observed across the wheat field, between the transmission lines and the main wreckage, beginning 100 feet north of the transmission lines and proceeding north- northeasterly to where the fuselage came to its final rest. The left side of the airplane's fuselage was crushed in. The engine was broken free of the mounts and separated from the airplane. Both wings were separated from the airplane at the roots. The right wing was found resting next to the fuselage. It was bent, twisted, and crushed inward. The left wing was broken into several pieces and found scattered between the first impact mark and the main wreckage. Both main gear were bent up and aft onto the fuselage. The left horizontal stabilizer was broken off at the root. The vertical stabilizer, rudder, right horizontal stabilizer and right elevator were undamaged. The propeller remained attached to the flange and exhibited torsional bending and chordwise scratching. Part of a transmission line was found wrapped around the propeller. Flight control continuity was confirmed. Examination of the engine, engine controls and other airplane systems revealed no anomalies.

Aircraft

Registration
N23640
Reported as
Air Tractor AT-301
Category
Airplane
Serial number
AT301-405
Airframe hours
4,087
Engine
P&W R-1340, 600 horsepower, reciprocating
Damage
Substantial damage
Flight
Aerial application · Part 137
Registered owner
Krech & Kroeplin LLC
Airworthiness certificate
Special, Restricted (Special)
Last inspection
Annual · March 17, 1997 · 63 hours before
Departed
HON

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
38
Certificate
Commercial
Airplane ratings
Single-engine land
Medical
Class 1, Valid Medical--w/ waivers/lim
Seat
Front
Flight hours
2,732 total · 812 in this make and model · 2,648 as pilot in command · 129 in the last 90 days · 129 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
190° at 8 knots
Visibility
10 statute miles
Lowest ceiling
3,800 ft overcast
Temperature
57 °F, dew point 52 °F
Altimeter
29.00 inHg
Observed at
HON, 12 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.

Other investigations on N23640 · 1

Matched to the same aircraft by N-number and date.