ATL89MA070 · Swearingen SX-300
Swearingen SX-300 · Accident: airframe, component or system failure en route
From Wright-Patterson Air Force Base (FFO) to an unrecorded destination
Event
- NTSB case
- ATL89MA070
- 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
- 2 · 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
Swearingen SX-300
- Aircraft type
- Swearingen SX-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
- N6Y
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Wright-Patterson Air Force Base (FFO), Dayton, OHTo 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
- 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
- Destroyed
Cause areas
- Production/design personnel › Inadequate quality control
- Wing, wing attachment fitting › Fatigue
- Wing, wing attachment fitting › Fractured
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
THIS SX-300 (SA-29) WAS A PROOF-OF-CONCEPT ACFT BEING DEMONSTRATED FOR THE USAF AT WRIGHT-PATTERSON AFB. THE ACFT WAS CLEARED TO RESTRICTED AREA R5503 AT 8000 FT FOR A DEMONSTRATION. RADIO COMMUNICATIONS WITH INDIANAPOLIS ARTCC WERE ROUTINE; THERE WERE NO DISTRESS TRANSMISSIONS. ABOUT 7 MINUTES AFTER TAKEOFF THE ACFT WAS INVOLVED IN AN INFLIGHT BREAKUP. THE WRECKAGE PATH WAS ABOUT 1 MILE IN LENGTH WITH THE RT WING 3000 FEET FROM THE MAIN WRECKAGE. THE RT WING LOWER ATTACHMENT FITTING EXHIBITED A FATIGUE AREA WHICH PROGRESSED TO FAILURE FROM A WELD NUGGET NEAR THE INTERSECTION OF TWO WELD BEADS. PRE-EXISTING CRACKS WERE ALSO PRESENT IN THE LUG WELD AREA OF THE LEFT WING UPPER AND LOWER ATTACH- MENT FITTINGS. THE ACFT HAD BEEN IN SVC 571 HRS. IT WAS CERTIFIED AS AN EXPERIMENTAL CATEGORY EXHIBITION ACFT. THE DESIGNER HAD STATIC LOAD TESTED THE WINGS TO 6 G'S & SUSPECTED THE ACFT HAD BEEN SUBJECTED TO FLT LOADS APCHG 6 G'S. THE PLT TOLD AN ACQUAINTANCE THAT HE HAD ROUTINELY EXCEEDED THE 'RED LINE' BY 85 MPH.
Probable cause
FATIGUE AND RESULTING FAILURE OF THE RIGHT WING'S LOWER ATTACHMENT FITTING AND INADEQUATE QUALITY CONTROL BY THE SWEARINGEN SX-300 PRODUCTION/DESIGN PERSONNEL.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ATL89MA070
- Event ID
- 20001213X27542
- Case number
- ATL89MA070
- 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: e7213b7fd41bb92ff2637bb38cec06e92d80f77b7e58b4fdcf693a899943d852; retrieved 2026-09-21T03:25:55.859Z.