# NTSB SEA90LA131: Cessna TU206G, N4953Z, Roche Harbor, WA, July 11, 1990

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 11, 1990, 14:15 local (21:15 UTC)
- Place: Roche Harbor, WA
- Coordinates: 48.529037, -123.060951 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=48.5290&lon=-123.0610&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 5 uninjured
- Status: Completed, report February 12, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 41236
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA90LA131
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41236/pdf
- Page: https://openairdocs.org/ntsb/SEA90LA131

## Probable cause

THE PILOT'S FAILURE TO MAINTAIN DIRECTIONAL CONTROL AFTER ENCOUNTERING UNSTABLE ATMOSPHERIC CONDITIONS DURING FINAL APPROACH TO LANDING.

## Sequence of events

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

- Loss of control - in flight, approach - vfr pattern - final approach
  - weather condition - downdraft (contributing factor)
  - directional control - not maintained, pilot in command (cause)
  - weather condition - turbulence (contributing factor)
- On ground/water collision with object, landing - roll
  - object - tree(s) (contributing factor)
  - terrain condition - ditch (contributing factor)

## Analysis

THE PILOT OF THE CESSNA TU206G ATTEMPTED A LANDING AT A PRIVATE AIRSTRIP ON SPIEDEN ISLAND. AT THE APPROACH END OF THE RUNWAY, THE AIRPLANE ENCOUNTERED A DOWNDRAFT AND THE PILOT LOST DIRECTIONAL CONTROL DURING THE RECOVERY ATTEMPT.

## Aircraft

- Registration: N4953Z (not matched to a registry record)
- Reported make and model: CESSNA TU206G
- Category: Airplane
- Serial number: U20606857
- Engines: CONTINENTAL TSIO-520RCM 310 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Michael W. Shimasaki
- Registered owner: Unknown
- Departed: BFI, SEATTLE, WA
- Destination: SPIDEN ISLAND, WA
- Airport: NONE, Spieden Isl., runway 9, 1,800 × 30 ft, grass/turf

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 31; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; flight hours: 187 total, 132 in this make and model, 134 as pilot in command, 4 in the last 90 days, 1 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 50 statute miles
- Lowest ceiling: none
- Temperature: -0 °F, dew point -0 °F

## 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 19900711025439A](https://openairdocs.org/incident/19900711025439A), Jul 11, 1990: Cessna TU206G, Roche Harbor, WA, Substantial damage. Stalled on final approach. Bounced, veered off side of runway. Struck rocks.

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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