CEN19LA231 · Ayres S2R G10
Earl's Spray Service Ayres S2R G10 · Accident: loss of engine power (total) during initial climb
From Breckenridge, MI (private airstrip) to Breckenridge, MI (private airstrip)
Event
- NTSB case
- CEN19LA231
- 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
Ayres S2R G10
- Aircraft type
- Ayres S2
- 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
- N766BF
- Operator
- Earl's Spray Service
- Onboard fatalities
- Unknown
- Route
- From Breckenridge, MI (private airstrip)To Breckenridge, MI (private airstrip)
- Aircraft age
- About 20 years (built 1999)
- 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
- Initial climb
- 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 departing on an agricultural application flight when after takeoff, about 100 ft above the ground, he observed a sudden increase in exhaust gas temperature (EGT) above the engine’s limitations. The pilot immediately reduced the throttle, but the engine had a total loss of engine power and the pilot made an immediate forced landing in a cornfield. The airplane fuselage and wings were substantially damaged during the forced landing.
Data downloaded from the airplane’s engine monitor confirmed there was a sudden and total loss of engine oil pressure that resulted in a loss of control of the propeller blade angle with a corresponding decrease in engine speed and increase of EGT. The decrease in oil pressure was consistent with a low oil supply to the main oil pump.
It was reported that engine oil was present in the oil tank, but the oil level was not verified at the accident site. However, a few weeks after the accident, the engine oil tank did not contain any oil when the engine was prepared for shipment. The oil tank was intact and was not breached. Additionally, the oil transfer hoses and fittings associated with the oil cooler were found intact and tight.
Postaccident disassembly of the engine did not reveal any evidence of a mechanical malfunction or failure that would have precluded normal operation. Normal oil wetting and wear signatures were observed throughout the engine. The investigation determined that the loss of engine oil was not from the engine.
The airframe portion of the engine oil system, consisting of the oil cooler and two transfer flex-hoses, was examined to determine the source of the oil leak. Although there was a weld fracture along the edge of the cooler housing, the fracture location and appearance were consistent with impact-related damage. The weld was repaired and there were no leaks observed with the oil cooler or the two transfer flex-hoses when they were pressurized and submerged in a water tank.
A review of photos taken on the day of the accident revealed that there was engine oil present on several components inside the engine nacelle. The internal surface of the eductor mixing duct also was oil wetted, consistent with engine exhaust drawing escaped oil from the nacelle through the annulus and into the mixer duct.
The oil cooler was replaced 2 days and 1.74 flight hours before the accident flight. Although an inadequately torqued oil flex-hose fitting likely was the source of the inflight loss of engine oil, the investigation was unable to conclusively support this scenario with the information collected during the investigation.
Probable cause
A total loss of engine power due to a lack of oil in the engine. The source of the inflight oil leak could not be determined based on the available information.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN19LA231
- Event ID
- 20190722X93824
- Case number
- CEN19LA231
- 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: a3a1ea8954b624eaeaa9f5cfd142585cda2a475693e361928686b7107b4aa3da; retrieved 2026-09-16T09:31:14.359Z.