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CEN09FA340 · Gulfstream American Corp AA-5B

7 Jun 2009 · Humbird, WI, United States

Gulfstream American Corp AA-5B · Accident: VFR encounter with IMC en route

From Lake Elmo Airport (21D) to Sheboygan County Memorial Airport (KSBM)

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Event

NTSB case
CEN09FA340
Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
Accident
InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
Completed
API-reported fatalities
2 · all aircraft and ground
Ground fatalities
Unknown
OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
General aviation
WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
Instrument Meteorological Cond

Gulfstream American Corp AA-5B

Category
Airplane
RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
N448DM
Operator
Unknown
Onboard fatalities
Unknown
Route
From Lake Elmo Airport (21D), Lake Elmo, MNTo Sheboygan County Memorial Airport (KSBM), Sheboygan, WI
Aircraft age
Not recorded
Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
Part 91: General Aviation
Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
En route · cruise
Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
VFR encounter with IMC
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
Substantial

Cause areas

  • Environmental issues › Conditions/weather/phenomena
  • Personnel issues › Psychological
  • Personnel issues › Task performance

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

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.

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.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record CEN09FA340
Event ID
20090608X00552
Case number
CEN09FA340
Dataset
full-current
Source SHA-256
5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
  • Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
  • Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
  • The date is the local date, which is the same as the UTC date the NTSB stores.
  • API snapshot SHA-256: fc8e1ed44b44d6d995ecc92b3c3e4818324e5718272ce6b4328e3b42f68e9eeb; retrieved 2026-09-13T20:10:49.508Z.