Pilot Debrief

Gulfstream American Corp AA-5B near Humbird, WI — 2009-06-07

Final reportCEN09FA340
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Date
2009-06-07
Location
Humbird, WI, USA
Aircraft
Gulfstream American Corp AA-5B
Registration
N448DM
Category
Airplane
Highest injury
Fatal
Fatalities
2
Phase of flight
Preflight

Probable cause

The pilot's decision to attempt a visual flight rules flight into an area of known instrument meteorological conditions, which resulted in a loss of control due to spatial disorientation.

NTSB narrative

The non-instrument-rated private pilot obtained two weather briefings before departing on the visual flight rules (VFR) cross-country flight. During the weather briefings he was advised that VFR flight was not recommended because of an active weather advisory for widespread instrument meteorological conditions that encompassed his planned route. The weather advisory was for occasional cloud ceilings below 1,000 feet above ground level (agl) and surface visibilities less than 3 miles with light precipitation/mist. The forecast weather was for ceilings 1,500 to 2,500 feet agl with widely scattered light rain showers and isolated thunderstorms. Approximately 1 hour after departure, several witnesses located near the accident site reported hearing an airplane overfly their position. These witnesses noted that because of a low cloud ceiling, fog, and light precipitation they could not see the airplane. The witnesses reported hearing the sound of an airplane engine operating at a high speed. Several witnesses noted that the loudness of the airplane's engine increased and decreased several times, as if the airplane was turning, before they heard a ground impact. The distribution of the wreckage was consistent with an airplane that experienced a loss of control and an in-flight breakup at low altitude and high airspeed. The challenging visibility conditions were conducive to the onset of pilot spatial disorientation and the airplane's rapid, near-vertical descent is consistent with the pilot's loss of control of the airplane because of spatial disorientation. The postaccident investigation revealed no preexisting mechanical malfunctions or anomalies that would have prevented the normal operation of the airplane or its systems.

Analysis

Primary failure mode
VFR into IMC
First missed decision gate
Pilot should have canceled the flight after multiple weather advisories against VFR.

NTSB coding

Evidence available

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

Docket documents28

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