# NTSB CHI74IC091: Swearingen SA226T, N423S, Chicago, IL, May 16, 1974

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Closed
- Date: May 16, 1974
- Place: Chicago, IL · CHICAGO, IL
- Location: 41.8500° N, 87.6501° W: Placed by OpenAirDocs: center of Chicago, IL, within about 9 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=41.8500&lon=-87.6501&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 15 uninjured
- Status: Completed, report October 30, 1974
- Report: Brief approved by the director
- Safety recommendations: Yes
- NTSB case key (mKey): 80142
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI74IC091
- Page: https://openairdocs.org/ntsb/CHI74IC091

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
5-0030  74/5/16  NR.CHICAGO,ILL        SWEARINGEN SA226T   CR-  0  0  2  COMMERCIAL                AIRLINE TRANSPORT, AGE
        TIME - 1443                    N423S               PX-  0  0 13  COMMUTER AIR CARRIER      35, 11500 TOTAL HOURS,
                                       DAMAGE-MINOR        OT-  0  0  0  AIR TAXI-PASSG S-D        490 IN TYPE, INSTRUMENT
                                                                                                   RATED.
        CLASSIFIED AS INCIDENT
        DEPARTURE POINT             INTENDED DESTINATION
          CHICAGO,ILL                 LAFAYETTE,IND
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           PROPELLER/ROTOR FAILURE: PROPELLER                       IN FLIGHT: NORMAL CRUISE
        PROBABLE CAUSE(S)
           PERSONNEL - PRODUCTION-DESIGN-PERSONNEL: SUBSTANDARD QUALITY CONTROL
           POWERPLANT - PROPELLER SYSTEM: BLADES
           MISCELLANEOUS ACTS,CONDITIONS - FATIGUE FRACTURE
        FACTOR(S)
           MISCELLANEOUS ACTS,CONDITIONS - SEPARATION IN FLIGHT
        EMERGENCY CIRCUMSTANCES - PRECAUTIONARY LANDING ON AIRPORT
                                  SUSPECTED OR KNOWN AIRCRAFT DAMAGE
                                  PROP/ENGINE VIBRATION
        REMARKS- FATIGUE CRACK ORIGD AT SMALL STRESS CORROSION CRACK.144HRS.BLADE HIT PARKED AUTO.
```

## Aircraft

- Registration: N423S (not matched to a registry record)
- Reported make and model: SWEARINGEN SA226T
- Category: Airplane
- Engines: turbo prop
- Damage: Minor damage

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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