MKC83FA084 · Cassutt III M SPORT III M SPOR
Cassutt III M SPORT III M SPOR · Accident: airframe, component or system failure en route
From Manhattan Regional Airport (MHK) to Dane County Regional Truax Field (MSN)
Event
- NTSB case
- MKC83FA084
- 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
- 0
- 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
Cassutt III M SPORT III M SPOR
- Aircraft type
- Cassutt III M SPORT
- 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
- N1790
- Operator
- John A. Rolfsmeyer · private individual
- Onboard fatalities
- Unknown
- Route
- From Manhattan Regional Airport (MHK), Manhattan, KSTo Dane County Regional Truax Field (MSN), Madison, WI
- Aircraft age
- Not recorded
- 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 91: General Aviation
- 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
- En route · cruise
- First occurrenceThe 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
- Airframe, component or system failure
- 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
- Fluid, oil › Leak
- Lubricating system › Loose
- Other maintenance personnel › Maintenance, improper
- Window, flight compartment window/windshield › Dirty(foggy)
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
WHILE EN ROUTE AT 5500 FT MSL, THE PLT NOTICED AN OIL FILM START TO COVER THE WINDSHIELD OF THE HOME BUILT ACFT. AT THAT TIME, HE WAS APPROACHING HIAWATH, KS, SO HE DIVERTED TO THE HIAWATHA ARPT. BY THE TIME HE ENTERED THE TRAFFIC PATTERN TO LAND, THE OIL RESTRICTED HIS FORWARD VISIBILITY. ON FINAL APPROACH, THE PLT S-TURNED TO KEEP HIMSELF ORIENTED WITH THE RWY. AFTER TOUCHDOWN, THE ACFT VEERED OFF THE RWY & THE GEAR COLLAPSED. AN INVESTIGATION REVEALED THE CRANKSHAFT PLUG, LYCOMING PN STD-1211, WAS LOOSE & DISTORTED, THUS ALLOWING OIL TO EXIT THE ENG AT THE PROPELLER. THE PLT STATED THAT AN OIL LEAK HAD PREVIOUSLLY DEVELOPED. HE SAID A MECHANIC USED A HAMMER TO RESEAT THE PLUG. AN EXAM OF THE PLUG REVEALED AN OFF-CENTERED INDENTATION ON THE PLUG'S FACE & DRIED SILICONE ADHESIVE AROUND ITS OUTER CIRCUMFERENCE.
Verbatim NTSB analysis from the NTSB dataset
Sources
NTSB record MKC83FA084
- Event ID
- 20001214X42538
- Case number
- MKC83FA084
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
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. 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: 7682f0a8179c5b77e480dea06ad370e0f9b99d4c6758b1b8593a5040796762c2; retrieved 2026-09-23T22:36:35.051Z.