Amateur-built Sonerai II accident near Grantsburg, Wisconsin, April 22, 2009
On April 22, 2009 at about 7:00 pm local time, a amateur-built Sonerai II, registered N232PE, was destroyed in an accident during initial climb near Grantsburg, Wisconsin (Circle T Airport). It was a personal flight under general aviation rules (Part 91). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's failure to maintain airspeed during initial climb which resulted in a stall/spin. Contributing to the accident was the degraded engine performance.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 22, 2009 · about 7:00 pm local time
- Place
- Grantsburg, Wisconsin · Circle T Airport · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built Sonerai II
- Registration
- N232PE · no longer on the register · serial 406
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The accident flight was the pilot’s first flight in the amateur-built, experimental airplane he had purchased about 7 months prior to the accident. A witness reported that the pilot was taxiing up and down the runway while revving the engine. The witness stated that the engine was missing on at least one cylinder during takeoff. He stated that the airplane climbed and made a left turn directly over his house, clearing it by about 80 feet. While in the turn, the wings dipped to the right, and then the wings dipped to the left “real hard.” The airplane rolled inverted and went down nose first. A Federal Aviation Administration airworthiness inspector examined the wreckage at the accident site. The inspection of the airplane revealed flight control continuity.The engine was a Continental O-200 series engine, but the engine data plate was missing so the exact model and serial number could not be identified. The mechanical and electrical engine controls were present. The magneto P-lead wires were still attached to the ignition switch and magnetos. There was oil in the engine and the crankshaft could rotate but not “very far.” The pilot had a history of depression, anxiety, and sleep apnea, and had been prescribed multiple medications for the conditions. The level of a prescription antidepressant found on post-accident toxicology was more than 10 times higher than expected given the pilot's prescription for the medication. He had broken his left ankle, and had surgical screws placed for the non-healing fracture a week prior to the accident. He had recently taken narcotic and over-the-counter pain medications. The pilot had not reported any of his chronic health problems to the FAA, and it is unlikely that the FAA would have approved medical certification for him had complete information been provided.
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
- Loss of engine power (partial) during takeoff
- Aerodynamic stall/spin during initial climb defining event
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
The NTSB's findings
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Airspeed › Not attained/maintained
- Personnel issues › Physical › Health/Fitness › Use of medication/drugs › Pilot
- Personnel issues › Physical › Alertness/Fatigue › (general) › Pilot
- factor Aircraft › Aircraft power plant › Power plant › (general) › Damaged/degraded
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 402 hours in all; 0 in this make and model
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: ctr
- Injury: fatal
The aircraft
- Maximum gross weight: 1,150 lb
- Seats: 1
- Landing gear: fixed
- Engine: Continental O-200 (piston); 0 hours total
- Fire on the ground
The flight
- Departed from: WS77 Grantsburg WI at 7:00 pm
- Destination: WS77 Grantsburg WI
- Flight plan: none
- Runway 27, 2,115 ft by 96 ft
Weather at the time
- Light: daylight
- Wind: from 290° at 7 knots
- Visibility: 10 statute miles
- Sky: overcast at 2,600 ft
- Temperature: 57°F (14°C), dew point 18°F (-8°C)
- Altimeter: 29.90 inHg
- Observation at 6:52 pm from MSP, 60 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 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.
