CHI02LA206

NTSB accident investigation · Air Tractor AT-401B · Pratt, KS · July 22, 2002

Accident · No injuriesLimited investigationFinal report
Date
July 22, 2002, 10:40 local (15:40 UTC)
Place
Pratt, KS
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N60747Air Tractor AT-401B
Weather
Visual (VMC) · Day
Status
Completed · report September 30, 2003
Report
Approved by Office Director
Parties
Federal Aviation Administration
FAA report
20020722017579A
Case key
55272

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 terrain clearance. A factor was low altitude flight.

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 terrain/waterManeuvering - aerial application
Altitude - lowPilot in commandFactor
Clearance - not maintainedPilot in commandCause
Terrain condition - ground

Analysis

The aerial application flight descended into the corn crops that the pilot was spraying before impacting the ground. The pilot was attempting to roundout and level the airplane at an altitude of 5-10 feet above the corn when he noticed the airplane settling into the corn. He then added power and pitched the nose up slightly, but the descent continued into the corn and terrain. No mechanical anomalies were noted that would have precluded normal operation.

Factual narrative

On July 22, 2002, at 1040 central daylight time, an Air Tractor AT-401B, N60747, operated by Farmers Spraying Service Inc., was substantially damaged when it impacted terrain during an approach to a cornfield. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 137 aerial application flight was not operating on a flight plan. The airline transport pilot was uninjured. The local flight originated from the Pratt Industrial Airport (PTT), Pratt, Kansas, at 1028.

The pilot stated in a written statement that he departed to spray a cornfield field located about 4.3 nautical miles northwest of PTT. Upon his arrival at the cornfield, he determined that the wind was from the northeast about 10 mph from smoke, which he placed over his pivot point. Cumulus clouds were forming with high humidity and a slightly gusty breeze. He observed power lines bordering the west and south sides of the corn field. He decided to spray the field in a north/south race track pattern. He set up for a shallow downline coming over the power lines on his second lap or fourth pass over the field with his airspeed increasing through 95 mph (30-32 inches of manifold pressure and 2,175 rpm). He began to roundout 5-10 feet above the corn, but the airplane continued its downline. He then added full power and pitched up slightly, but the airplane settled into the corn.

Inspection of the accident site by the Federal Aviation Administration revealed the airplane contacted the corn crops about 309 feet north of the south power lines. The wreckage path consisted of the left spray boom located about 513 feet north of the power lines, a ground scar located about 792 feet north of the power lines, and the airplane which was 1,143 feet north of the power lines. The airplane was upright and facing towards the southwest. The airplane sustained damage to the rear fuselage, tail section and landing gear. The outboard sections of the propeller were curled backwards. Flight control and engine continuity was confirmed.

The pilot stated that he had about 300 gallons of CAPTURE 2EC chemical and estimated that there were 232 gallons remaining at the time of the accident. He also reported the fuel tanks were about 2/3 full.

The Great Bend, Kansas, Automated Weather Observing Station, located about 35 nautical miles north-northwest, recorded at 1055: wind 360 at 11 knots gusting to 15 knots; temperature 24 degrees Celsius (C); altimeter setting 30.05 inches of mercury. The station elevation is 1,887 feet. The density altitude was about 3,264 feet.

Aircraft

Registration
N60747
Reported as
Air Tractor AT-401B
Category
Airplane
Serial number
1000
Airframe hours
1,835.6
Engine
Pratt & Whitney R1340, 600 horsepower, reciprocating
Damage
Substantial damage
Flight
Aerial application · Part 137
Registered owner
Farmers Spraying Service Inc
Airworthiness certificate
Special, Restricted (Special)
Last inspection
Annual · January 14, 2002 · 227.6 hours before
Departed
PTT · Pratt, KS
Destination
PTT
Airport
PTT · Pratt Industrial 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
35
Injuries
None
Certificates
Commercial, Airline transport
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 2, Valid Medical--w/ waivers/lim
Last flight review
May 13, 2002
Seat
Single
Flight hours
5,400 total · 1,505 in this make and model · 5,380 as pilot in command · 149 in the last 90 days · 89 in the last 30 days · 3 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
360° at 11 knots, gusting 15
Visibility
10 statute miles
Lowest ceiling
2,200 ft broken
Temperature
75 °F, dew point 70 °F
Altimeter
30.04 inHg
Observed at
GBD, 35 nm away

Docket · 3

The files NTSB released with the investigation on July 18, 2003, on NTSB’s docket system: statements, records, photos and specialists’ reports. 542 KB in all.

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 N60747 · 1

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