Pilot Debrief

Air Tractor AT 502 near Harlingen, TX — 2019-04-09

Final reportCEN19FA117
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Date
2019-04-09
Location
Harlingen, TX, USA
Aircraft
Air Tractor AT 502
Registration
N7314D
Category
Airplane
Highest injury
Fatal
Fatalities
1
Phase of flight
Descent

Probable cause

The pilot’s failure to maintain clearance from power transmission lines during low altitude flight operations. Contributing to the accident was the pilot’s impairment due to a sedating medication.

Contributing factors

Contributing to the accident was the pilot’s impairment due to a sedating medication.

NTSB narrative

The pilot was conducting an agricultural flight when witnesses observed the airplane flying at a low altitude before it collided with power transmission lines and terrain. The airplane was destroyed during a postimpact fire. Examination of the airplane wreckage did not reveal any preimpact mechanical malfunctions or failures that would have precluded normal operation. Toxicology testing detected the sedating antihistamine diphenhydramine in the pilot’s blood. Considering that postmortem redistribution of diphenhydramine may result in central levels being two-to-three times higher than peripheral levels, the circulating level was likely in the therapeutic range at the time of the accident. Given the pilot’s years of experience and familiarity with the agricultural airplane, it is reasonable to consider diminished reaction times and flying performance attributable to the use of sedating medication likely contributed to the accident.

Analysis

Primary failure mode
Human factors
First missed decision gate
Pilot could have avoided low altitude flight near power lines.

NTSB coding

Evidence available

  • Photos
  • 12 docket documents
View NTSB final reportView NTSB docket

Docket documents12

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