Pilot Debrief

BELL 47G 5 near MANSFIELD, IL — 2014-08-12

Final reportCEN14LA423
Sign in to save
Date
2014-08-12
Location
MANSFIELD, IL, USA
Aircraft
BELL 47G 5
Registration
N7089J
Category
Helicopter
Highest injury
Fatal
Fatalities
1
Phase of flight
Maneuvering

Probable cause

The pilot's failure to maintain clearance from power lines during low-altitude flight in gusting wind conditions following his use of a sedating medication.

NTSB narrative

The commercial pilot was conducting an agricultural application flight in the helicopter and had just completed spraying a field. A witness near the accident site reported that he saw the helicopter flying low and then pass a tree line when a wind gust lifted the helicopter up and to the left directly into power lines. Weather conditions reported at an airport in the area included wind at 16 knots gusting to 21 knots at the time of the accident. Separated power lines were observed near the accident site, and a witness mark was melted into the leading edged of a main rotor blade, consistent with it contacting a power line. Recorded GPS data were consistent with low-altitude operations near the accident site. Based on the evidence, it is likely that, while the pilot was flying low-altitude operations in gusting wind conditions, he failed to maintain adequate clearance from power lines. Toxicology testing detected the sedating antihistamine diphenhydramine in the pilot's urine and in his heart blood. Although some degree of impairment from diphenhydramine cannot be completely ruled out, the pilot's behavior on the day of the accident, as evidenced by GPS data that shows he flew straight lines and made good coverage of the fields during the spraying, was consistent with his level of skill and experience. Therefore, it is unlikely that the pilot's impairment from diphenhydramine contributed to the accident.

Analysis

Primary failure mode
Loss of control
First missed decision gate
Pilot could have avoided low altitude flight in gusty wind conditions.

NTSB coding

Evidence available

  • 10 docket documents
View NTSB final reportView NTSB docket

Docket documents10

Related mishaps