Piper PA-25 accident near Wh Sulphur Spgs, Montana, July 11, 1989
On July 11, 1989 at about 8:45 pm local time, a Piper PA-25, registered N6663Z, was substantially damaged in an accident near Wh Sulphur Spgs, Montana. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 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 FAILED TO MAINTAIN ADEQUATE AIRSPEED DURING AN AERIAL APPLICATION MANEUVER AND INADVERTENTLY ALLOWED THE AIRCRAFT TO MUSH INTO THE GROUND. UNFAVORABLE WIND AND TURBULENCE WERE CONSIDERED TO BE CONTRIBUTING FACTORS.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 11, 1989 · about 8:45 pm local time
- Place
- Wh Sulphur Spgs, Montana · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Piper PA-25 · all PA-25s on the register
- Registration
- N6663Z · no longer on the register · serial 25-2263
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
THE PLT WAS ON AN AERIAL APPLICATION FLT, SPRAYING WEEDS NEXT TO HILLY TERRAIN. HE RPRTD THAT AS HE WAS IN A RIGHT TURN (LAST SPRAY RUN), THE ACFT ENCOUNTERED AN UNEXPECTED TAILWIND & EXTREME TURBULENCE. SUBSEQUENTLY, IT SETTLED & COLLIDED WITH THE GROUND.
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
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land; instrument: airplane
- Flight time: 3,674 hours in all; 2,000 in this make and model; 330 in the last 90 days; 100 in the last 30 days
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: unk
The aircraft
- Last inspection: inspection type not recorded; 0 hours since
- Maximum gross weight: 2,500 lb
- Seats: 1
- Landing gear: fixed
- Engine: Lycoming O-540 (piston); 0 hours total
The flight
- Departed from: 7S6 Wh Sulphur Spgs MT
- Destination: 7S6
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 360° at 15 knots
- Visibility: 15 statute miles
- Sky: clear
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| 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.