Air Tractor AT-502 N502WQ

Summary

On 5 August 2006 at about 11:08 local time, a Air Tractor AT-502 registered N502WQ, operated by Thiel Air Care, Inc., was involved in an accident near Chowchilla, California, United States. One person was on board and one died. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

5 August 2006 at 11:08

Classification

Accident

Location

Chowchilla, California, United States

Coordinates

37.0356, -120.3575

Aircraft

Air Tractor AT-502

Registration

N502WQ

Category

Airplane

Engines

1

Operator

Thiel Air Care, Inc.

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

Chowchilla → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Night/Dark

NTSB number

LAX06LA255

1 person died.

The pilot's loss of control while maneuvering resulting from an incapacitating physiological event.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

Near the end of an aerial application flight, the pilot maneuvered the airplane 1/3-mile northwest of the designated field and began reversing course. A flagger in the field reported observing the airplane's main light turn on, which was unusual because the airplane was neither over a designated spray field nor an airstrip. Thereafter, the airplane rolled completely inverted and impacted the ground. About 6 weeks earlier, the pilot had experienced pain related to the presence of a kidney stone. He reported pain in his abdominal area, in his right flank, and above his hip. The pilot was taken to the hospital and was diagnosed as having 2 kidney stones; one in the ureter and one nearer the kidney. Days later, the pilot passed 2 fragments of the ureter stone; however, the one nearer the kidney was likely still there. When the pilot reported for work on the morning of the accident day, company personnel observed him rubbing his sides above his hip, indicative of the remaining stone inducing pain and discomfort. The pilot reported that he felt somewhat uncomfortable and he felt "some pain in his sides." The operator reported that the activation switch for the airplane's lights is located on the flight control stick. The operator simulated holding onto the control stick and doubling over. When these actions were performed, the airplane was capable of quickly rolling inverted. The pilot likely experienced a significant incapacitating event due to pain from the kidney stone, which resulted in his losing control of the airplane.

Quoted verbatim from the NTSB record.