# NTSB SEA90FA091: Cessna 172K, N79931, Tacoma, WA, June 3, 1990

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: June 2, 1990, 23:23 local (Jun 3, 1990, 06:23 UTC)
- Place: Tacoma, WA
- Coordinates: 47.109485, -122.590583 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=47.1095&lon=-122.5906&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed, report November 9, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 41111
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA90FA091
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41111/pdf
- Page: https://openairdocs.org/ntsb/SEA90FA091

## Probable cause

THE PILOT DID NOT ADEQUATELY MAINTAIN A PROPER GLIDE PATH FOR LANDING WHICH RESULTED IN AN INFLIGHT COLLISION WITH A TREE.

## Sequence of events

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

- In flight collision with object, approach - vfr pattern - final approach
  - weather condition - drizzle/mist (contributing factor)
  - altimeter setting - improper, pilot in command (contributing factor)
  - lack of recent total experience, pilot in command (contributing factor)
  - light condition - dark night (contributing factor)
  - proper glidepath - inadequate, pilot in command (cause)
  - object - tree(s)
  - weather evaluation - poor, pilot in command (contributing factor)

## Analysis

DURING A VFR FLIGHT, THE FLIGHTS INTENDED DESTINATION WAS REPORTING IFR CONDITINS. THE PILOT OPTED TO DIVERT TO ANOTHER AIRPORT THAT WAS REPORTING VFR. DURING THE DESCENT FOR LANDING ON FINAL APPROACH, THE AIRPLANE COLLIDED WITH TREES. POST CRASH INVESTIGATION DID NOT REVEAL ANY MECHANICAL FAILURES OR MALFUNCTIONS. THE COCKPIT INTRUMENT PANEL WAS DESTROYED DURING THE IMPACT SEQUENCE. THE FACE OF THE ALTIMETER, HOWEVER, WAS RETRIEVED. THE BAROMETRIC PRESSURE WINDOW DISPLAYED A SETTING OF 30.10 IN HG. THE LAST SETTING AIR TRAFFIC GAVE TO THE PILOT JUST PRIOR TO ACCIDENT WAS 30.02 IN HG, A DIFFERENCE OF .08 IN OR 80 FEET WHICH WOULD HAVE INDICATED THAT THE AIRPLANE WAS 80 FEET HIGHER THAN ITS ACTUAL ALTITUDE ABOVE GROUND LEVEL.

## Aircraft

- Registration: [N79931](https://openairdocs.org/deregistered/N79931-1991-10-10), registration cancelled 1991-10-10, S/N 17258258 (OpenAirDocs)
- Reported make and model: CESSNA 172K
- Registry model: [Cessna 172K](https://openairdocs.org/model/cessna-172k) (registry code 2072430) (OpenAirDocs)
- Category: Airplane
- Serial number: 17258258
- Airframe hours: 4625
- Engines: LYCOMING O-320-E2D 150 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Operator: Gower Flying Service
- Registered owner: L. Sheffels And Sons Inc
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, April 2, 1990, 71 hours before
- Departed: WA38, MONROE, WA
- Destination: OLM, OLYMPIA, WA
- Airport: GRF, Gray Aaf, runway 33, 6,100 ×  ft, dirt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 807 total, 52 in this make and model, 756 as pilot in command

## Weather

- Conditions: Visual (VMC), Night/dark
- Wind: calm
- Visibility: 5 statute miles
- Lowest ceiling: 4,000 ft
- Temperature: 57 °F, dew point 54 °F
- Altimeter: 30.00 inHg
- Observed at: GRF, 1 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 19900602018179A](https://openairdocs.org/incident/19900602018179A), Jun 2, 1990: Cessna 172K, Fort Lewis/Taco, WA, Destroyed, 1 fatal. Struck trees on final during night approach in light rain. Had altimeter set incorrectly. Fog layer on tree tops.

## Other investigations on N79931 (2)

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.

- [NTSB SEA77DYM58](https://openairdocs.org/ntsb/SEA77DYM58), Aug 19, 1977: Cessna 172K (N79931), Orchard, WA, substantial damage
- [NTSB SEA74DYE50](https://openairdocs.org/ntsb/SEA74DYE50), Jun 30, 1974: Cessna 172 (N79931), Burlington, WA, substantial 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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