FTW00LA212

NTSB accident investigation · Air Tractor AT-401 · Panhandle, TX · July 18, 2000

Accident · FatalLimited investigationFinal report
Date
July 17, 2000, 19:45 local (Jul 18, 2000, 00:45 UTC)
Place
Panhandle, TX
Injuries
1 fatal
Damage
Destroyed
Phase of flight
Maneuvering
Aircraft
N6055WAir Tractor AT-401
Weather
Visual (VMC) · Day
Status
Completed · report April 18, 2001
Report
Approved by Office Director
FAA report
20000717012429A
Case key
49743

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 airspeed, which resulted in a stall.

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
Airspeed - not maintainedPilot in commandCause
Stall - encounteredPilot in commandCause

Analysis

The airplane was fueled, loaded with chemical, and departed to spray a field. The airplane was making a climbing right turn to re-enter the field when the nose dropped and, subsequently, the airplane entered a steep descent and impacted the ground. According to data from a SATLOC GPS, most of the turns made during the flight had a diameter of 1,000 feet. The data ended with the airplane completing 230 degrees of a right turn with a diameter of 660 feet. Examination of the accident site revealed that the airplane impacted the ground in a near vertical attitude. Partial flight control continuity was established for the aileron and elevators, and continuity was established for the rudder. The engine and propeller exhibited evidence of producing power at the time of impact.

Factual narrative

On July 17, 2000, at 1945 central daylight time, an Air Tractor AT-401 agricultural airplane, N6055W, was destroyed when it impacted terrain while maneuvering near Panhandle, Texas. The airplane was registered to and operated by Stamps Spraying Service, Inc., of Panhandle, Texas. The commercial pilot, sole occupant of the airplane, sustained fatal injuries. Visual meteorological conditions prevailed and a flight plan was not filed for the 14 Code of Federal Regulations (CFR) Part 137 aerial application flight. The local flight originated from the operator's private grass airstrip.

According to the operator, the airplane was fueled, loaded with an herbicide chemical, and departed to spray a field. When the pilot arrived at the field, he radioed back to the operator and stated that he was worried about chemical drift due to the wind speed and direction. A few minutes later, the pilot radioed the operator again and stated that he would commence spraying the field.

According to witnesses, the airplane was spraying chemical prior to the accident. One witness reported that the airplane was making a climbing turn and then nose dived into the ground. Another witness stated that he observed the airplane make one pass, initiate a "pull-up," and enter a right bank. He added that the airplane "did not pull out of the right bank and nose dived into the ground."

According to the FAA inspector and a representative from Air Tractor Inc., who examined the airplane at the site, the airplane came to rest at North 034 degrees 00.000 minutes latitude and West 068 degrees 54.375 minutes longitude. The engine and propeller were embedded within the initial impact crater, and the propeller blades exhibited "S" type bending. Two ground scars consistent with the shape of the leading edge of the wings were observed emanating outward from the crater. The cockpit and cabin area was destroyed by impact forces and the leading edges of both wings were compressed rearward to the main spar. Aileron control continuity was established from the control surface to the inboard section of each wing. Further continuity for the ailerons was precluded by impact damage to the fuselage and cockpit area. The empennage remained intact, although it sustained structural damage. Control continuity for the rudder was established from the rudder pedals to the control surface. Control continuity for the elevators was precluded due to impact damage, although continuity for the elevator trim system was established between the cockpit and the elevator trim tabs. An unidentified substance, which resembled pipe insulation, was installed between the elevators and the stabilizers as a gap seal. The flap actuator was located and the jackscrew was extended between 3.5 and 3.75 inches, which is consistent with the flaps being extended between 25 and 26 degrees.

According to data that was extracted from a SATLOC GPS unit, which was found at the accident site, the majority of turns had diameters measuring approximately 1,000 feet. The last turn recorded on the unit revealed that the airplane completed 230 degrees of a turn and the turn had a diameter of 660 feet. The data stops at a location near the accident site on a heading of approximately 280 degrees.

An autopsy was performed on the deceased pilot by the Lubbock County Medical Examiner's Office, Lubbock, Texas. Toxicological testing, performed by the FAA's Civil Aeromedical Institute, Oklahoma City, Oklahoma, revealed that there was putrefaction of the body and 50mg/dL, mg/hg of ethanol detected in the kidney, 10mg/dL, mg/hg of acetaldehyde detected in the kidney, and 1mg/dL, mg/hg detected in the kidney. The toxicological tests were negative for drugs.

Aircraft

Registration
N6055W
Reported as
Air Tractor AT-401
Category
Airplane
Serial number
401-0963
Engine
P&W R-1340-AN1, 600 horsepower, reciprocating
Damage
Destroyed
Flight
Aerial application · Part 137
Registered owner
Stamps Spraying Service Inc.
Airworthiness certificate
Special, Restricted (Special)
Last inspection
Annual · March 6, 2000
Departed
NONE

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
Certificate
Commercial
Airplane ratings
Single-engine land
Medical
Class 2, Valid Medical--w/ waivers/lim
Seat
Center
Toxicology
Performed
Flight hours
5,000 total · 245 in this make and model

Weather

Conditions
Visual (VMC) · Day
Wind
190° at 8 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
91 °F, dew point 57 °F
Altimeter
30.00 inHg
Observed at
AMA, 15 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.