Pilot Debrief

DOUGLAS AD-4N near Twin Falls, ID — 2011-03-08

Final reportWPR11FA156
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Date
2011-03-08
Location
Twin Falls, ID, USA
Aircraft
DOUGLAS AD-4N
Registration
N2088G
Category
Airplane
Highest injury
Fatal
Fatalities
2
Phase of flight
Cruise

Probable cause

The non-instrument-rated pilot’s encounter with localized instrument meteorological conditions, which resulted in spatial disorientation and a loss of airplane control.

NTSB narrative

The non-instrument-rated pilot was on a cross-country flight when the airplane impacted terrain. According to limited radar data, after departure the flight proceeded northwest and climbed to 6,500 feet mean sea level (msl). Only segments of the flight were visible due to the low altitude range of the radar. The flight track continued northeast to its last target at an altitude of 7,900 feet msl and about 0.25 mile from the accident site. Terrain elevation at the accident site was about 6,600 feet msl. A postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. Ground scar analysis, impact signatures, and wreckage fragmentation patterns indicated that the airplane impacted terrain in a steep, nose-down attitude with high forward velocity. Analysis of available weather information indicated that conditions likely produced restricted visibility in the area at the time of the accident. The restricted visibility conditions would have been conducive to the development of spatial disorientation.

Analysis

Primary failure mode
Spatial disorientation
First missed decision gate
Pilot could have chosen to avoid flying in deteriorating weather conditions.

NTSB coding

Evidence available

  • ADS-B / radar
  • Photos
  • 10 docket documents
View NTSB final reportView NTSB docket

Docket documents10

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