# NTSB MKC86FA059: Swearingen SA226TC, N252AM, Kansas City, MO, February 15, 1986

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Field investigation · Final report
- Date: February 14, 1986, 20:33 local (Feb 15, 1986, 02:33 UTC)
- Place: Kansas City, MO
- Location: 39.0997° N, 94.5786° W: Placed by OpenAirDocs: center of Kansas City, MO, within about 10 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=39.0997&lon=-94.5786&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 16 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 34059
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MKC86FA059
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/34059/pdf
- Page: https://openairdocs.org/ntsb/MKC86FA059

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Airframe/component/system failure/malfunction, climb - to cruise
  - propeller system/accessories,blade - fatigue (cause)
  - maintenance - improper, other maintenance personnel (cause)
  - propeller system/accessories,blade - separation
  - engine assembly - vibration
  - engine assembly,mount - overload

## Analysis

DURING A CLIMB TO CRUISE, THE PILOT-IN-COMMAND DECLARED AN EMERGENCY & REQUESTED TO DSCND & RETURN TO THE ARPT. THE LANDING WAS UNEVENTFUL. AN EXAM OF THE LEFT PROP REVEALED THAT 1 OF ITS 3 BLADES HAD FAILED AT THE BUTT END & HAD SEPARATED. SUBSEQUENTLY, THE LEFT ENG ATTACH MOUNTS HAD FAILED & THE ENG HAD BECOME COCKED OUTBOARD FROM ITS ORIGINAL POSITION. A METALLURGICAL EXAM OF THE BLADE REVEALED FATIGUE CRACKING, EMINATING FM WITHIN THE PILOT HOLE OF THE BLADE BUTT. NUMEROUS SCRATCHES WERE VISIBLE IN THE PILOT HOLE AND THE CRACK HAD ITS INITIATION AT ONE OF THE SCRATCH MARKS NR THE BEARING WASHER. THE WASHER IS USED TO PULL THE BEARING OUT OF THE PILOT HOLE FOR MAINTENANCE AND/OR INSPECTION.

## Aircraft

- Registration: [N252AM](https://openairdocs.org/deregistered/N252AM-1992-09-01), registration cancelled 1992-09-01, S/N TC408 (OpenAirDocs)
- Reported make and model: SWEARINGEN SA226TC
- Registry model: [Swearingen SA226TC](https://openairdocs.org/model/swearingen-sa226tc) (registry code 8780404) (OpenAirDocs)
- Category: Airplane
- Serial number: TC-408
- Airframe hours: 2374
- Engines: AIRESEARCH TPE-331 840 horsepower turbo prop
- Damage: Substantial damage
- Flight: Part 135
- Registered owner: Air Midwest Inc.
- Airworthiness certificate: Standard, Transport
- Last inspection: AAIP, January 26, 1986, 75 hours before
- Departed: MCI, KANSAS CITY, MO
- Destination: MZV, MOLINE, IL
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 30; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 8,193 total, 6,036 in this make and model, 7,350 as pilot in command, 185 in the last 90 days, 90 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 300° at 4 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 16 °F, dew point 7 °F
- Altimeter: 30.00 inHg
- Observed at: MCI, 30 nm away

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19860214004849A](https://openairdocs.org/incident/19860214004849A), Feb 14, 1986: Swrngn SA226TC, Kansas City, MO, Substantial damage. Left engine lost a prop blade on climbout. Imbalance tore engine loose and remaining blades penetrated the cabin.

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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