# NTSB SEA89LA149: Swanson RV-4, N9RS, Carnation, WA, August 13, 1989

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: August 13, 1989, 11:05 local (18:05 UTC)
- Place: Carnation, WA
- Coordinates: 47.640953, -121.890869 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=47.6410&lon=-121.8909&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious, 1 minor
- Status: Completed, report June 30, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 41062
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA89LA149
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41062/pdf
- Page: https://openairdocs.org/ntsb/SEA89LA149

## Probable cause

THE PILOT ENTERED AN INADVERTENT STALL AND HIT TREES WHILE PERFORMING AEROBATICS.

## Sequence of events

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

- Loss of control - in flight, maneuvering
  - aerobatics - performed, pilot in command
  - stall - inadvertent, pilot in command
- In flight collision with object, descent - uncontrolled
  - object - tree(s)

## Analysis

DURING A LOCAL PLEASURE FLIGHT, THE AIRPLANE WAS OBSERVED TO BE PERFORMING HIGH SPEED LOW PASSES IN A VALLEY BEFORE IT BEGAN A LOOP MANEUVER. AS THE AIRPLANE COMPLETED THE LOOP, IT BEGAN TO IMMEDIATELY CLIMB AND CLEAR RISING TERRAIN. THE AIRPLANE STALLED AND COLLIDED WITH TREES BEFORE THE PILOT REGAINED CONTROL. THERE WERE NO REPORTED MECHANICAL FAILURES OR MALFUNCTIONS WITH THE AIRPLANE AT THE TIME OF THE ACCIDENT.

## Aircraft

- Registration: [N9RS](https://openairdocs.org/deregistered/N9RS-2013-06-14), registration cancelled 2013-06-14, S/N 7, built 1986 (OpenAirDocs)
- Reported make and model: SWANSON RV-4
- Registry model: [Swansen Roger D RV-4](https://openairdocs.org/model/swansen-roger-d-rv-4) (registry code 05608Y6) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Airplane, amateur-built
- Serial number: 7
- Engines: LYCOMING O-320-E2A 150 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Roger D. Swansen
- Airworthiness certificate: Special, Experimental (Special)
- Departed: S36, KENT, WA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 37; private; airplane ratings: single-engine land; medical: class 3, expired; seat: front; flight hours: 1,350 total, 60 in this make and model, 1,350 as pilot in command, 5 in the last 90 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 220° at 6 knots
- Visibility: 20 statute miles
- Lowest ceiling: 20,000 ft broken
- Temperature: 72 °F, dew point 52 °F
- Altimeter: 30.00 inHg
- Observed at: BFI, 14 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 19890813029009A](https://openairdocs.org/incident/19890813029009A), Aug 13, 1989: Amtrvn VANSRV4, Carnation, WA, Substantial damage. After low passes over residences looped at tree top level. Unable to recover struck trees. Medical also expired.

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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