Air Tractor AT-301 accident near Grangeville, Idaho, April 17, 1989
On April 17, 1989 at about 4:15 pm local time, a Air Tractor AT-301, registered N4340S, was substantially damaged in an accident near Grangeville, Idaho (Idaho County airport). It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A PARTIAL POWER LOSS DUE TO A BLOWER FAILURE. A FACTOR RELATED TO THE ACCIDENT WAS THE SOFT FIELD CONDITION.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 17, 1989 · about 4:15 pm local time
- Place
- Grangeville, Idaho · Idaho County · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Air Tractor AT-301
- Registration
- N4340S · no longer on the register · serial 301-0020
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
A PARTIAL POWER LOSS OCCURRED DRG INITIAL CLIMB. THE PLT JETTISONED HIS LOAD & LANDED IN A SOFT FIELD ABOUT 3/4 MI FROM THE RWY, WHERE THE ACFT NOSED OVER. A FIRE ERUPTED, WHICH SELF-EXTINGUISHED MINUTES LATER. THE OPERATOR RPRTD THAT A 10 INCH DROP IN MANIFOLD PRESSURE HAD OCCURRED & THAT A SUSPECTED BLOWER FAILURE WAS THE REASON FOR THE POWER LOSS.
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: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane single-engine; instrument: airplane
- Flight time: 2,052 hours in all; 38 in this make and model; 75 in the last 90 days; 42 in the last 30 days; 1,952 as pilot in command; 500 on instruments
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: ctr
The aircraft
- Airframe total time: 5,745 hours
- Last inspection: annual inspection, November 28, 1988; 72 hours since
- Maximum gross weight: 5,000 lb
- Seats: 1
- Landing gear: fixed
- Engine: P&W R-1340-AN-1 (piston); 0 hours total
- Fire on the ground
The flight
- Flight plan: none
- Runway 7, 4,800 ft by 60 ft
Weather at the time
- Light: daylight
- Wind: from 045° at 2 knots
- Visibility: 15 statute miles
- Sky: broken clouds at 2,500 ft; not recorded
- Temperature: 45°F (7°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.