Piper PA-18-150 accident near Okaton, South Dakota, December 11, 2012
On December 11, 2012 at about 3:00 pm local time, a Piper PA-18-150, registered N3471Z, was substantially damaged in an accident during takeoff near Okaton, South Dakota (Private Airstrip airport). It was a personal flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's failure to perform an adequate preflight inspection of the airplane and obstruction of the aileron control system by snow and ice, which led to a loss of control during flight.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- December 11, 2012 · about 3:00 pm local time
- Place
- Okaton, South Dakota · Private Airstrip · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA-18-150 · all PA-18-150s on the register
- Registration
- N3471Z · registry record · serial 18-7291
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that 2 days before the accident, snow accumulated on the airplane’s wings while it was parked in an open front hangar. The day before the accident, the temperature was warmer, and the pilot believed that the snow melted and ran rearward to the aileron gap/hinge locations, re-freezing during the nighttime hours. On the day of the accident, the pilot was in a hurry to use the airplane to check his pastures and brushed the snow off of the wings but did not perform a thorough preflight check of the airplane, including checking freedom of movement of the ailerons. After takeoff, the airplane began turning to the left. The pilot attempted to correct the turn, but the airplane did not respond. When he looked out at the wings, he could see that the ailerons were not responding to control inputs as they should. As he was attempting to regain control, the airplane descended into trees, resulting in substantial damage to both wings, the fuselage, and tail surfaces. A postaccident examination of the airplane revealed no mechanical defects that were determined to have existed before the accident.
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
- Aircraft inspection event during prior to flight
- Loss of control in flight during takeoff defining event
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
The NTSB's findings
- cause Personnel issues › Task performance › Inspection › Preflight inspection › Pilot
- cause Aircraft › Aircraft systems › Flight control system › Aileron control system › Inadequate inspection
- cause Environmental issues › Conditions/weather/phenomena › Temp/humidity/pressure › Conducive to structural icing › Contributed to outcome
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 2,000 hours in all; 600 in this make and model
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: frt
- Injury: no injuries
The aircraft
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming O-320 SERIES (piston); 0 hours total
The flight
- Departed from: PVT Okaton SD at 3:00 pm
- Destination: PVT Okaton SD
- Flight plan: none
- Runway 09
Weather at the time
- Light: daylight
- Wind: from 320° at 5 knots
- Visibility: 10 statute miles
- Sky: overcast at 9,500 ft; not recorded
- Temperature: 19°F (-7°C), dew point 16°F (-9°C)
- Altimeter: 29.85 inHg
- Observation at 2:55 pm from PHP, 37 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.