Air Tractor AT-401 accident near Aurora, Nebraska, August 4, 1995
On August 4, 1995 at about 2:45 pm local time, a Air Tractor AT-401, registered N4543F, was substantially damaged in an accident near Aurora, Nebraska. 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 cracked engine assembly that caused the power loss during a critical phase of flight. Factors associated with this accident were the restricted airplane performance due to the power loss, the airplane's altitude was too low, and remedial action, by, the pilot, that would lead to an uneventful forced landing was not possible.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 4, 1995 · about 2:45 pm local time
- Place
- Aurora, Nebraska · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Air Tractor AT-401
- Registration
- N4543F · no longer on the register · serial 401-0787
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
AT THE BEGINNING OF THE PILOT'S SWATH RUN HE NOTICED WHITE SMOKE COMING FROM THE RIGHT SIDE OF THE ENGINE. HE SAID HE DISCONTINUED THE RUN AND TURNED BACK TOWARD HIS HOME AIRPORT. JUST AS THE AIRPLANE LEVELED OUT FROM ITS TURN THE PILOT SAID THE ENGINE LOST MOST OF ITS POWER. THE PILOT SAID HE HEADED THE AIRPLANE FOR A PASTURE BUT WAS UNABLE TO GLIDE TO IT. THE AIRPLANE NOSED OVER SHORTLY AFTER ITS WHEELS CONTACTED THE CORN, COMING TO REST ON THE GROUND. EXAMINATION OF THE ENGINE REVEALED THE NUMBER 4 CYLINDER'S EXHAUST TOWER WAS CRACKED WHERE THE ROCKER ARM SHAFT WENT THROUGH THE CYLINDER HEAD. THE OWNER/MECHANIC OF THE AIRPLANE SAID THE CONDITION RESULTING FROM THE DAMAGED EXHAUST TOWER PREVENTS THE CYLINDER'S EXHAUST VALVE FROM OPENING. THE RESULT OF THE EXHAUST VALVE NOT OPENING CREATES A BLOW BACK CONDITION THAT AFFECTS THE OTHER CYLINDERS. THE END RESULT, ACCORDING TO THE OWNER, IS THAT THE ENGINE WILL LOSE MOST OF ITS POWER. THIS WAS CONFIRMED BY THE FAA PRINCIPAL MAINTENANCE INSPECTOR WHO CONDUCTED THE ENGINE EXAMINATION.
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: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instrument: airplane
- Flight time: 10,220 hours in all; 1,600 in this make and model; 190 in the last 90 days; 100 in the last 30 days; 9,750 as pilot in command; 880 on instruments
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: ctr
The aircraft
- Airframe total time: 1,439 hours
- Last inspection: annual inspection, April 10, 1995; 187 hours since
- Maximum gross weight: 7,860 lb
- Seats: 1
- Landing gear: fixed
- Engine: P&W R-1340-AN-1 (piston); 0 hours total
The flight
- Departed from: AUH NE at 2:20 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 100° at 8 knots
- Sky: broken clouds at 1,100 ft; not recorded
- Temperature: 75°F (24°C), dew point 70°F (21°C)
- Altimeter: 30.00 inHg
- Observation at 3:56 pm from GRI, 15 miles away
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.
Other NTSB records under N4543F the same tail number, which may have belonged to a different aircraft at the time
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.