CHI00LA189 · Staudacher Aircraft, Inc. S-300D2
Staudacher Aircraft, Inc. S-300D2 · Accident: airframe, component or system failure while maneuvering
From Kenosha Regional Airport (ENW) to an unrecorded destination
Event
- NTSB case
- CHI00LA189
- 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
Staudacher Aircraft, Inc. S-300D2
- Aircraft type
- Staudacher S-300
- 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
- N112KG
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Kenosha Regional Airport (ENW)To not recorded
- 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
- Maneuvering
- 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
- Flight control, aileron attachment › Fatigue
- Flight control, aileron › Separation
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot was performing a 1/2 snap roll when the left aileron departed the airframe. The aircraft was still controllable and an uneventful landing was made. The spherical rod end bearing that was used for the center aileron hinge had broken and a subsequent metallurgical was performed. Energy dispersive spectroscopy (EDS) examination revealed "... only iron and manganese consistent with plain carbon steel. There were no appreciable amounts of chromium, nickel, or molybdenum as might be expected with an AISI 4130 or AISI 8420 material." The report also states that the "... microstructure and hardness is typical of a normalized or annealed, medium carbon steel." The metallurgical report states that the rod end fracture was due to "... reverse bending fatigue (from cycling about its lateral axis) initiating at the root of the shank threads." The aircraft designer said that the accident aircraft had a different style rod bearing installed than the original design. The designer stated that he believed that the new rod end bearing shank was made of the same material and heat treat as the original. The specification for the original rod end bearing shows that the shank is to be made from AISI 4130 or AISI 8420 steel.
Probable cause
The fatigue failure of the rod end bearing and the separation of the aileron. A factor was the inadequate design change by the aircraft designer.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI00LA189
- Event ID
- 20001212X21381
- Case number
- CHI00LA189
- 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: 52b3bb1258bb92baebc34f4d7ee6c17413f0ac19eb5ebc35f67d0064752e3258; retrieved 2026-09-22T12:43:22.071Z.