Pilot Debrief

GULFSTREAM AMERICAN CORP AA-5A near Lakeview, OR — 2012-05-25

Final reportWPR12FA237
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Date
2012-05-25
Location
Lakeview, OR, USA
Aircraft
GULFSTREAM AMERICAN CORP AA-5A
Registration
N26837
Category
Airplane
Highest injury
Fatal
Fatalities
1
Phase of flight
Climb

Probable cause

The pilot’s decision to take off in known adverse weather conditions and his subsequent failure to maintain sufficient airspeed while maneuvering in mountainous terrain and an area of low ceilings, snow, and fog, which resulted in a loss of airplane control.

NTSB narrative

The pilot dropped off two passengers at an airport where overcast clouds and occasional snow showers were present and then departed for the return flight to the original departure airport. GPS data indicated that during the return flight the airplane crossed mountainous/hilly terrain. When the pilot reached the western edge of the last mountain ridge, he turned and flew in a northerly direction along its steep western slope. The pilot then performed a 180-degree turn, during which the airplane’s groundspeed increased significantly in a short period of time. Just after the pilot rolled out of the turn, the airplane’s groundspeed suddenly decreased below that required to maintain flight, and, almost immediately, the airplane descended into the terrain. A review of weather information indicated that the base of the overcast cloud layer was below the tops of some of the terrain in this area. Snow showers, strong wind, and patches of fog were present beneath the overcast. It is likely that the pilot flew into the adverse weather or was maneuvering around it when the loss of airplane control occurred. Postaccident examination of the airframe and engine revealed no evidence of a mechanical malfunction or failure that would have precluded normal operation.

Analysis

Primary failure mode
VFR into IMC
First missed decision gate
Pilot continued flight into worsening weather despite zero visibility over mountains.

NTSB coding

Evidence available

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

Docket documents24

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