Piper PA-18-150 accident near Forsyth, Montana, August 18, 2011
On August 18, 2011 at about 3:25 pm local time, a Piper PA-18-150, registered N7666D, was substantially damaged in an accident during maneuvering near Forsyth, Montana (Frank Wiley Field). It was an aerial observation flight under general aviation rules (Part 91). 2 people were killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot’s failure to maintain adequate airspeed while maneuvering, which resulted in a stall/mush, loss of control, and impact with terrain.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 18, 2011 · about 3:25 pm local time
- Place
- Forsyth, Montana · Frank Wiley Field · map
- Type
- Accident
- Injuries
- 2 people were killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA-18-150 · all PA-18-150s on the register
- Registration
- N7666D · no longer on the register · serial 18-5935
- Damage
- Substantial damage
- Flight
- Aerial observation flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The operator reported that the pilot and passenger were going to survey a prairie dog town and take pictures. Hunters in the accident area observed the airplane fly overhead and descend below mountainous terrain while in a turn. The airplane crashed in an open field. The airplane damage and the ground scars at the accident site were consistent with the airplane being in a stalled condition at the time of the accident. The pilot likely failed to maintain adequate airspeed as he was increasing the bank angle to maintain visual reference to the ground, which resulted in a stall/mush, loss of control, and collision with terrain. A postaccident examination of the airframe and engine revealed no evidence of a mechanical failure or malfunction that would have precluded normal operation.
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 control in flight during maneuvering defining event
- Collision with terrain or object (not controlled flight into terrain) during maneuvering
The NTSB's findings
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Airspeed › Not attained/maintained
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Angle of attack › Not attained/maintained
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
- Environmental issues › Physical environment › Terrain › (general) › Not specified
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land; instrument: airplane
- Flight time: 3,000 hours in all; 500 in this make and model
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: frt
- Injury: fatal
The aircraft
- Last inspection: inspection type not recorded
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming O-320 SERIES (piston); 0 hours total
- Fire on the ground
The flight
- Departed from: MLS Miles City MT
- Destination: MLS Miles City MT
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 190° at 4 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 72°F (22°C), dew point 45°F (7°C)
- Altimeter: 29.90 inHg
- Observation at 2:53 pm from MLS, 32 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.