NTSB Identification: FTW99LA140.
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Accident occurred Friday, May 14, 1999 in BROWNWOOD, TX
Probable Cause Approval Date: 06/21/2000
Aircraft: Air Tractor AT-301, registration: N4329S
Injuries: 1 Minor.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

The pilot stated that during the 3 weeks prior to the accident, he had averaged 15-hour work days. On the day of the accident, the pilot's first flight, which was a ferry flight to the airstrip, commenced at 0600. At 0722, he began the aerial application flights. At 1203, the airplane returned from the 20th application flight and was refueled. During the refueling, the pilot retracted the flaps to 'improve the footing' of the person who was fueling the left main fuel tank. The pilot stated that he did not extend the flaps prior to the 21st takeoff, and he did not use a checklist. The pilot stated that after takeoff the 'airplane wouldn't climb.' The airplane impacted trees during the initial climb after takeoff. The airplane flight manual requires that the flaps be extended 10 degrees prior to takeoff with a full hopper load or from a 'short' runway. The flap actuator jack screw and ball nut assembly were examined, and the ball nut was observed within 1/4 inch of the large gear-box ball bearing on the jack screw. This finding is consistent with the flaps being in the retracted position.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

The failure of the pilot-in-command to use the manufacturer's published checklist and extend the flaps prior to takeoff. A factor was the pilot's fatigued physiological condition as a result of extended flight and ground duty hours.

Full narrative available

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