CHI02LA259

NTSB accident investigation · Air Tractor AT-402A · Cherokee, IA · August 25, 2002

Accident · Serious injuriesLimited investigationFinal report
Date
August 25, 2002, 10:00 local (15:00 UTC)
Place
Cherokee, IA
Injuries
1 serious
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N9032KAir Tractor AT-402A
Weather
Visual (VMC) · Day
Status
Completed · report May 13, 2003
Report
Approved by Office Director
Parties
FAA
FAA report
20020825027769A
Case key
55592

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 failed to maintain clearance with the power lines resulting in the rudder separation and the subsequent loss of aircraft control. A factor associated with the accident was the power line that was contacted.

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
Loss of control - in flightApproach
Aircraft control - not possiblePilot in commandCause
Flight control,rudder surface - separationCause
In flight collision with terrain/waterDescent - uncontrolled
Terrain condition - ground

Analysis

The airplane contacted power lines during an aerial application flight. The pilot reported he was making a swath run along a set of power lines that ran north and south through the middle of a field when the airplane contacted another set of power lines that ran east and west along the north edge of the field. The top 10 inches of the vertical stabilizer and the rudder separated from the airplane. The pilot reported that when the rudder separated, the rudder pedals were "pulled tight against the hopper" which resulted in him having no rudder control. In addition, he stated that he only had "some" aileron control. The pilot reported that about one-half mile from the airport, he pulled the power back to 1,000 pounds of torque and the airplane began to bank to the right. He reported that he was unable to control the bank with the ailerons. According to the pilot, the airplane then banked to the left, the nose pitched up, and the airplane "rolled over on its back." He reported the nose then dropped and the airplane descended into the ground.

Factual narrative

On August 25, 2002, at 1000 central daylight time, an Air Tractor AT-402A, N9032K, operated by Bakke Flying Service, contacted power lines during an aerial application flight in Cherokee, Iowa. The airplane then contacted the terrain while attempting to land at the Cherokee Municipal Airport (CKP), Cherokee, Iowa. The commercial rated pilot was seriously injured. The airplane received substantial damage. The Title 14 CFR Part 137 aerial application flight was operating in visual meteorological conditions without a flight plan. The flight originated from CKP at 0830.

The pilot reported he was making a swath run along a set of power lines that ran north and south through the middle of a field when the airplane contacted another set of power lines that ran east and west along the north edge of the field. The top 10 inches of the vertical stabilizer and the rudder separated from the airplane. The pilot reported that when the rudder separated, the rudder pedals were "pulled tight against the hopper." He stated that he could no longer reach the rudder pedals with his feet and he was not able to free them up. He reported that he had no rudder control and "some" aileron control.

The pilot reported the airplane was heading toward the airport, so he continued in that direction at tree top height. He reported he contacted the Unicom at the airport, informed them of what happened and requested that they call the fire department and an ambulance.

The pilot reported that about one-half mile from the airport, he pulled the power back to 1,000 pounds of torque and the airplane began to bank to the right. He reported that he was unable to control the bank with the ailerons. According to the pilot, the airplane then banked to the left, the nose pitched up, and the airplane "rolled over on its back." He reported the nose then dropped and the airplane descended to impact with the ground.

Aircraft

Registration
N9032K
Reported as
Air Tractor AT-402A
Category
Airplane
Serial number
402B-1105
Airframe hours
758
Engine
Pratt & Whitney PT6-15, 680 horsepower, reciprocating
Damage
Substantial damage
Flight
Aerial application · Part 137
Operator
Vance J. Bakke
Registered owner
Jerome V. Bakke
Airworthiness certificate
Special, Restricted (Special)
Last inspection
Annual · April 10, 2002 · 119 hours before
Departed
CKP · Cherokee, IA
Destination
CKP · Cherokee, IA
Airport
CKP · Cherokee Municipal

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
Injuries
Serious
Certificate
Commercial
Airplane ratings
Single-engine land
Medical
Class 2, Valid Medical--no waivers/lim.
Last flight review
February 8, 2002
Seat
Center
Flight hours
5,500 total · 870 in this make and model

Weather

Conditions
Visual (VMC) · Day
Wind
290° at 3 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
73 °F, dew point 63 °F
Altimeter
30.12 inHg
Observed at
SLB, 17 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.