# NTSB SEA87FA036: Swearingen SA227AC, N164SW, Salt Lake City, UT, December 16, 1986

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Field investigation · Final report
- Date: December 15, 1986, 19:27 local (Dec 16, 1986, 02:27 UTC)
- Place: Salt Lake City, UT
- Coordinates: 40.809848, -111.939392 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=40.8098&lon=-111.9394&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 4 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 40512
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA87FA036
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/40512/pdf
- Page: https://openairdocs.org/ntsb/SEA87FA036

## Sequence of events

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

- In flight encounter with weather, approach - faf/outer marker to threshold (ifr)
  - weather condition - fog (contributing factor)
  - weather condition - obscuration (contributing factor)
  - weather condition - below approach/landing minimums (contributing factor)
  - missed approach - attempted, copilot/second pilot
- In flight collision with object, missed approach (ifr)
  - flight/nav instruments,altimeter - incorrect (contributing factor)
  - minimum descent altitude - not identified, copilot/second pilot (cause)
  - flight/nav instruments,attitude indicator - false indication (contributing factor)
  - proper alignment - not maintained, copilot/second pilot (cause)
  - supervision - inadequate, pilot in command (cause)
  - diverted attention, pilot in command (contributing factor)
  - expectancy, pilot in command (contributing factor)
  - object - approach light/navaid (contributing factor)
- In flight collision with terrain/water, missed approach (ifr)
  - landing gear,main gear - previous damage (cause)

## Analysis

THE F/O WAS AT THE CONTROLS FOR THE ILS APCH TO SLC. FOG SEEDING WAS IN PROGRESS, PRODUCING VARIABLE VISIBILITIES. THE APCH COMMENCED WITH RVR WELL ABOVE CAT I MINS. AT DECISION HEIGHT(DH), THE CAPT CALLED 'LIGHTS IN SITE'. THE F/O CONTINUED THE APCH DESCENT THRU DH. THE ACFT THEN REENTERED IMC AND THE CAPT CALLED FOR MISSED APCH. THE F/O ADDED PWR AND ESTABLISHED A WINGS LEVEL, 10 DEG NOSE-UP ATTITUDE ON THE GYRO HORIZON AS THE CAPT EXECUTED CHECK LIST ITEMS. THE CAPT THEN NOTED THE ACFT WAS HEADING 20 DEGS RIGHT OF COURSE AND THE RIGHT WING DOWN ATTITUDE ON HIS GYRO HORIZON AT WHICH TIME HE CALLED 'TURN LEFT AND PULL UP.' THE ACFT LEFT MAIN LANDING GEAR CONTACTED A 45 FT HIGH ILS ANTENNA STACK 1049 FT DOWN THE RWY, 400 FT RIGHT OF CENTERLINE. THIS SEPARATED THE LEFT MAIN GEAR. THE ACFT DIVERETED TO PIH WHERE ADDITIONAL DAMAGE WAS SUSTAINED DURING LANDING. TESTS SHOWED THE F/O GRYO HORIZON HAD BAD BEARINGS AND THE 'OFF' FLAG WAS INOP. THE F/O'S ALTIMETER ALSO READ 100 FT HIGH.

## Aircraft

- Registration: N164SW (not matched to a registry record)
- Reported make and model: SWEARINGEN SA227AC
- Category: Airplane
- Serial number: 503
- Airframe hours: 11586
- Engines: GARRETT TPE-331 1000 horsepower turbo prop
- Damage: Substantial damage
- Flight: Part 135
- Operator: Skywest Airlines, Inc., doing business as Skywest Airlines/ Western Exp.
- Registered owner: General Elec. Credit Corp.
- Airworthiness certificate: Standard, Normal
- Last inspection: Continuous airworthiness, December 13, 1986, 21 hours before
- Departed: IDH, IDAHO FALLS, ID
- Destination: SLC, SALT LAKE CITY, UT
- Flight plan: IFR
- Airport: SLC, Salt Lake Int'L, runway 34L, 12,003 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 38; airline transport, commercial, flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 8,993 total, 6,476 in this make and model, 8,953 as pilot in command, 277 in the last 90 days, 107 in the last 30 days, 7 in the last 24 hours

## Weather

- Conditions: Instrument (IMC), Night/dark
- Wind: calm
- Lowest ceiling: 200 ft
- Temperature: 27 °F, dew point 25 °F
- Altimeter: 30.00 inHg
- Observed at: SLC

## 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 19861215067589A](https://openairdocs.org/incident/19861215067589A), Dec 15, 1986: Swrngn SA227AC, Salt Lake City, UT, Substantial damage. The aircraft struck a tower during missed approach. Copilot attitude indicator malfunctioned. Improper procedures.

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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