FTW00LA012

NTSB accident investigation · Air Tractor AT-301 · Olton, TX · October 14, 1999

Accident · Minor injuriesLimited investigationFinal report
Date
October 14, 1999, 10:13 local (15:13 UTC)
Place
Olton, TX
Injuries
1 minor
Damage
Substantial damage
Phase of flight
Maneuvering
Aircraft
N23930Air Tractor AT-301
Weather
Visual (VMC) · Day
Status
Completed · report June 21, 2000
Report
Approved by Office Director
FAA report
19991014044239A
Case key
49856

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 inflight separation of the propeller blade due to damage from a wire strike. A factor was the lack of suitable terrain for the forced landing.

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.

Airframe/component/system failure/malfunctionManeuvering - aerial application
Propeller system/accessories,blade - blade strikeCause
Propeller system/accessories,blade - separationCause
Forced landingEmergency descent/landing
Nose overLanding - roll
Terrain condition - none suitableFactor

Analysis

During an aerial application flight, one of the propeller blades of the agricultural airplane separated approximately midspan. The airplane began to shake violently, and the pilot executed a forced landing in a field. During the landing roll, the pilot applied the brakes to avoid colliding with an irrigation pipe, and the airplane nosed over and came to rest in the inverted position. Examination of the propeller, by an FAA inspector, revealed that it appeared to be damaged due to a wire strike. However, there were no broken high wires found in the immediate area of the accident site, and the pilot did not recall striking any wires. It could not be determined whether the damage had occurred just prior to the blade failure or if the blade had been damaged and not properly repaired prior to the flight.

Factual narrative

On October 14, 1999, at 1013 central daylight time, an Air Tractor AT-301 agricultural airplane, N23930, owned and operated by Burkett Flying Service of Sinton, Texas, nosed over during a forced landing following the in-flight separation of a portion of one propeller blade near Olton, Texas. The airplane sustained substantial damage, and the airline transport pilot, the sole occupant, received minor injuries. Visual meteorological conditions prevailed and no flight plan was filed for the 14 Code of Federal Regulations Part 137 local aerial application flight. The airplane departed from Littlefield, Texas, at 0820.

According to the pilot and the FAA inspector, who conducted an on site examination, the airplane was applying insecticide to cotton crops as part of the federally sponsored boll weevil eradication program. The airplane began to shake violently, and the pilot executed a forced landing in a field. During the landing roll, the pilot applied the brakes to avoid colliding with an irrigation pipe, and the airplane nosed over and came to rest in the inverted position. The top of the vertical stabilizer and rudder were crushed. Additionally, the engine mount was damaged, and the engine cowling was missing. The propeller remained attached to the engine. One of the propeller blades was intact, and the other blade was separated approximately midspan. The separated section of blade was not recovered. The engine cowling was recovered approximately 3/4-mile from the accident site.

A closer examination of the propeller, by another FAA inspector, revealed that it "appeared to have suffered damage caused by a wire strike; however, there were no broken high wires in the immediate area of the crash. The pilot did not recall striking any wires." The inspector stated that "it could not be determined whether the damage had occurred just prior to the blade failure or if it had been damaged and not properly repaired prior to operation."

Aircraft

Registration
N23930
Reported as
Air Tractor AT-301
Category
Airplane
Serial number
301-0465
Airframe hours
5,600
Engine
P&W R-1340, 600 horsepower, reciprocating
Damage
Substantial damage
Flight
Aerial application · Part 137
Registered owner
Burkett Flying Service
Airworthiness certificate
Special, Restricted (Special)
Departed
Q00 · Littlefield, 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
54
Certificates
Airline transport, Commercial
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--no waivers/lim.
Seat
Center
Flight hours
15,800 total

Weather

Conditions
Visual (VMC) · Day
Wind
0° at 0 knots
Visibility
10 statute miles
Lowest ceiling
0 ft
Temperature
81 °F, dew point 61 °F
Altimeter
29.00 inHg

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 N23930 · 1

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