Air Tractor AT-401 incident near Kenesaw, Nebraska, July 27, 2001
On July 27, 2001 at about 3:00 pm local time, a Air Tractor AT-401, registered N4553K, suffered minor damage in an incident near Kenesaw, 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 propeller blade fatigue leading to its tip separating during an aerial application. Factors were no suitable terrain for an emergency landing, high vegetation, and soft terrain encountered during the emergency landing.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 27, 2001 · about 3:00 pm local time
- Place
- Kenesaw, Nebraska · map
- Type
- Incident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Air Tractor AT-401
- Registration
- N4553K · no longer on the register · serial 401-0809
- Damage
- Minor damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
The airplane sustained minor damage when it nosed over during an emergency landing following an in-flight loss of a propeller blade tip. The pilot was uninjured. The pilot stated, "While on a actual spray run the aircraft began to shake and vibrate violently. At that time I shut the power down, climbed about 100 ft to look for a place to land. The area was rolling with pasture land and a corn field in front of me, no roads to land on in the area. ... After a rolling out for a short while in corn the landing gear became stuck in corn and soft sandy soil." A portion of the remaining blade, including the separation, was shipped to the NTSB's Materials Laboratory Division. The laboratory's report stated that "a large portion of the fracture surface was on a 90-degree flat plane with multiple ratchet marks and crack arrest marks on this portion of the fracture surface. These features are typical of a fatigue crack. The fatigue crack originated from multiple origins at the bottom of a gouge on the flat face of the blade about 2.25 inches from the blade's leading edge. The fatigue crack extended through about two-thirds of the blade's cross-section. The remainder of the fracture surface (about one-third of the blade's cross section) was on a 45-degree slanted plane and was typical of an overstress region stemming from the fatigue crack." A section was saw cut from the fracture containing the fatigue origin. The paint was removed from the areas near the crack origin and the surface was re-examined with a scanning electron microscope (SEM). The gouge was measured using the SEM. The report further stated, "The length of the gouge was 0.6 inch (1.5 millimeters), and the depth of the gouge was 0.0055 inch (0.14 millimeters). ... Optical examination of the flat face of the blade near the gouge did not show any evidence of blending or rework in this area." The propeller's last overhaul was completed on January 13, 1998. The propeller accumulated 240 hours of flight since that overhaul.
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
- Flight time: 7,259 hours in all; 1,000 in this make and model; 120 in the last 90 days; 70 in the last 30 days; 7,009 as pilot in command; 250 on instruments
- Last flight review: February 16, 2000
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: sngl
- Injury: no injuries
The aircraft
- Airframe total time: 1,397 hours
- Last inspection: annual inspection, June 7, 2001; 30 hours since
- Maximum gross weight: 6,000 lb
- Seats: 1
- Landing gear: fixed
- Engine: Pratt & Whitney R1340-AN1 (piston); 0 hours total
The flight
- Departed from: Roseland NE at 12:00 pm
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 170° at 7 knots
- Visibility: 10 statute miles
- Sky: broken clouds at 8,000 ft; a few clouds at 1,200 ft
- Temperature: 75°F (24°C), dew point 70°F (21°C)
- Altimeter: 30.04 inHg
- Observation at 3:53 pm from HSI, 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.
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.