Gulfstream American Corp AA-5B accident near Humbird, Wisconsin, June 7, 2009
On June 7, 2009 at about 10:45 pm local time, a Gulfstream American Corp AA-5B, registered N448DM, was substantially damaged in an accident during enroute (cruise) near Humbird, Wisconsin. It was a personal flight under general aviation rules (Part 91). 2 people were killed. The weather was instrument conditions (cloud, fog or low visibility).
The NTSB's probable cause their words, unchanged
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.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 7, 2009 · about 10:45 pm local time
- Place
- Humbird, Wisconsin · map
- Type
- Accident
- Injuries
- 2 people were killed.
- Weather
- instrument conditions (cloud, fog or low visibility)
- Aircraft
- Gulfstream American Corp AA-5B · all AA-5Bs on the register
- Registration
- N448DM · registry record · serial AA5B0976
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
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.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- VFR encounter with IMC during enroute (cruise) defining event
- Loss of visual reference during enroute (cruise)
- Loss of control in flight during enroute (cruise)
- Aircraft structural failure during uncontrolled descent
The NTSB's findings
- cause Personnel issues › Task performance › Planning/preparation › Weather planning › Pilot
- cause Environmental issues › Conditions/weather/phenomena › Ceiling/visibility/precip › Low ceiling › Decision related to condition
- cause Personnel issues › Psychological › Perception/orientation/illusio › Spatial disorientation › Pilot
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
- Aircraft › Aircraft structures › (general) › (general) › Capability exceeded
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 272 hours in all; 172 in this make and model; 19 in the last 90 days; 8 in the last 30 days; 190 as pilot in command
- Last flight review: February 15, 2009
- Medical certificate: Class 3 (without waivers/limitations)
- Seat: left
- Injury: fatal
The aircraft
- Airframe total time: 1,110 hours
- Last inspection: annual inspection, July 3, 2008; 53 hours since
- Maximum gross weight: 2,400 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming O-360-A4K (piston); 0 hours total
The flight
- Departed from: 21D Lake Elmo MN at 9:43 pm
- Destination: KSBM Sheboygan WI
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 090° at 9 knots
- Visibility: 10 statute miles
- Sky: overcast at 1,700 ft
- Temperature: 54°F (12°C), dew point 46°F (8°C)
- Altimeter: 29.95 inHg
- Observation at 10:56 pm from KEAU, 30 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.