CEN17LA309 · Air Tractor AT-802A
Lesco Aviation Air Tractor AT-802A · Accident: loss of engine power (total) while maneuvering
From Monmouth Municipal Airport (C66) to an unrecorded destination
Event
- NTSB case
- CEN17LA309
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Air Tractor AT-802A
- Aircraft type
- Air Tractor AT-802
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N528MB
- Operator
- Lesco Aviation
- Onboard fatalities
- Unknown
- Route
- From Monmouth Municipal Airport (C66), Monmouth, ILTo not recorded
- Aircraft age
- About 7 years (built 2010)
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 137: Agricultural
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Maneuvering · low-altitude flying
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Loss of engine power (total)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Aircraft › Aircraft power plant
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot was on an agricultural flight when the engine lost total power. The pilot completed a forced landing in a nearby field, but he was unable to maintain directional control of the airplane after it landed in the dense soybean crop. The outboard portion of the right wing and aileron were substantially damaged during the forced landing. A postaccident engine examination revealed that a single 1st stage compressor rotor airfoil had fractured near its root. The fatigue crack originated from a thinned leading edge due to significant erosion at the bottom of the airfoil pressure side; however, the exact location of the fatigue origin could not be determined because it had been obliterated by the erosion. The observed fracture features were consistent with a crack that had progressed in highcycle fatigue. Dimensional measurements of the fractured airfoil and the two adjacent airfoils revealed that they were under the minimum requirement for an airfoil. The airfoils also exhibited evidence of fine wear scratches, characteristic of fine abrasive particles impacting the airfoil, and thinning of their leading edges. The underlying cause of the airfoil erosion could not be determined with certainty; however, based on the observed damage, it was possibly the result of environmental conditions. The engine had accumulated 4,349.3 hours since new and had never been overhauled. The engine manufacturer’s recommended time between overhaul (TBO) was 3,000 hours; however, the operator was not required to comply with the recommended TBO interval under current regulations due to the type of operation.
Probable cause
A total loss of engine power due to the fracture of a single 1st stage compressor rotor airfoil in high-cycle fatigue as a result of the erosion and thinning of the airfoil's leading edge. Contributing to the fractured airfoil and loss of engine power was the operator’s decision to operate the engine past the manufacturer’s recommended time between overhaul.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN17LA309
- Event ID
- 20170810X14916
- Case number
- CEN17LA309
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, cause areas. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 1cae34c331fb92c6876aef674ea93d3623855778348d03f1d55077f48cce3100; retrieved 2026-09-16T05:41:13.515Z.