FTW95LA247

NTSB accident investigation · Air Tractor AT-301 · Guymon, OK · June 16, 1995

Accident · No injuriesLimited investigationFinal report
Date
June 16, 1995, 08:35 local (13:35 UTC)
Place
Guymon, OK
Injuries
1 uninjured
Damage
Destroyed
Phase of flight
Uncontrolled descent
Aircraft
N315PFAir Tractor AT-301
Weather
Visual (VMC) · Day
Status
Completed · report December 19, 1995
Report
Approved by Office Director
FAA report
19950616017959A
Case key
19456

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. The high density altitude was a factor.

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.

Loss of control - in flightDescent - uncontrolled
Weather condition - high density altitudeFactor
Airspeed - not maintainedPilot in commandCause
Stall/mush - encounteredPilot in command
In flight collision with objectCruise
Object - fence
In flight collision with terrain/waterDescent - uncontrolled

Analysis

The aerial application pilot departed his home base with a load of 305 gallons of solution. The pilot reported that 'it was immediately apparent that more power was required to maintain altitude and that the airplane was performing poorly.' While lining up for the first swath run, 'the airspeed dropped to 75 mph and a sink rate started that I couldn't stop even with full power and quarter flaps.' The airplane's landing gear struck a five strand barbed wire fence and the airplane impacted the ground substantially damaging the wing, landing gear, fuselage, and engine mount. The density altitude at the time of the accident was about 5,100 feet.

Factual narrative

On June 16, 1995, at 0835 central daylight time, an Air Tractor AT-301, N315PF, was substantially damaged while maneuvering near Guymon, Oklahoma. The airline transport rated pilot was not injured. The aircraft was owned and operated by Earl Kokendoffer, under Title 14 CFR Part 137. The flight originated from Guymon Municipal Airport near Guymon, Oklahoma, at 0825. Visual meteorological conditions prevailed for the local aerial application flight and a flight plan was not filed.

According to the Pilot/Operator Report, the pilot departed Guymon with 305 gallons of solution and "It was immediately apparent that more power was required to maintain altitude and that the airplane was performing poorly." A bank angle of more than 15 degrees resulted in a loss of altitude and airspeed. The pilot further stated that during the approach for the first swath, "the airspeed dropped to 75 mph and a sink rate started that I couldn't stop even with full power and quarter flaps."

As the airplane was flown under some high-power lines, "I was unable to arrest the sink rate and when the landing gear contacted a five strand barbed wire [fence] my remaining air speed was lost; the airplane quit flying." Substantial damage occurred to right wing, landing gear, fuselage, and engine mount.

Guymon Municipal Airport is at an elevation of 3,123 feet. At the time of the accident, the temperature was reported to be 79 degrees. The investigator-in-charge calculated the density altitude to be approximately 5,100 feet.

Aircraft

Registration
N315PF
Reported as
Air Tractor AT-301
Category
Airplane
Serial number
4000315
Engine
P&W R-1340-AN1, 600 horsepower, reciprocating
Damage
Destroyed
Flight
Aerial application · Part 137
Registered owner
Earl Kokendoffer
Airworthiness certificate
Special, Restricted (Special)
Last inspection
Annual · April 1, 1995
Departed
GUY · OK

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
50
Certificates
Airline transport, Commercial
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--w/ waivers/lim
Seat
Center
Flight hours
6,053 total · 60 in this make and model · 4,590 as pilot in command · 191 in the last 90 days · 53 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
180° at 8 knots
Visibility
15 statute miles
Lowest ceiling
None
Temperature
79 °F

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.