Amateur-built DHC-3 TURBO accident near West Seattle, Washington, December 19, 1984
On December 19, 1984 at about 7:08 pm local time, a amateur-built DHC-3 TURBO, registered N4247A, was substantially damaged in an accident near West Seattle, Washington (Boeing Field). It was a flight of an unrecorded kind under general aviation rules (Part 91). 1 person was seriously injured and 2 people had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The NTSB has not yet published a probable cause for this accident. Investigations usually take one to two years; this page updates when the final report is released.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- December 19, 1984 · about 7:08 pm local time
- Place
- West Seattle, Washington · Boeing Field · map
- Type
- Accident
- Injuries
- 1 person was seriously injured and 2 people had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built DHC-3 TURBO DHC-3 TURB
- Registration
- N4247A · no longer on the register · serial 421
- Damage
- Substantial damage
- Flight
- Flight of an unrecorded kind · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
ACFT WAS PERFORMING TEST FLT MANEUVERS WHEN PROBLEMS WITH THE MODIFIED FUEL SYSTEM OCCURRED. ICE BLOCKING A FUEL VENT LINE CAUSED A PARTIAL COLLAPSE OF THE MAIN (ENGINE FEED) FUEL CELL WHICH PRODUCED AN ERROUNEOUS FUEL QUANTITY READING. IN ADDITION, THE MAIN TANK OVERFLOW SHUTOFF VALVE WAS LEAKING, SO TANK OVERFLOW OCCURRED. THE FUEL OVERFLOW CAUTION LIGHT ILLUMINATED AND AUXILIARY TANK FUEL PUMP FEED TO MAIN AUTOMATICALLY SHUT DOWN. DUE TO MISCALIBRATION, THIS SYSTEM OVERRODE PLT ATTEMPTS TO RESTART AUX FUEL PUMPS. PLT REMAINED IN TEST AREA TROUBLESHOOTING RATHER THAN IMMEDIATE RETURN TO BASE, FINALLY NOTED MAIN TANK GAGE CONTINUING TO READ 'FULL.' EN ROUTE TO BOEING FIELD, FUEL STARVATION OCCURRED. PLTOPTED TO ATTEMPT FORCED LNDG IN SMALL ATHLETIC FIELD IN RESIDENTIAL AREA RATHER THAN DITCH IN PUGET SOUND. THE ACFT TOUCHED DOWN IN INTENDED LNDG AREA, THEN BOUNCED ACROSS AN ADJACENT STREET. THE ARRESTING ACTION OF TELEPHONE WIRES ON THE VERTICAL FIN BROUGHT THE ACFT TO REST IN A RESIDENTIAL BACKYARD.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: airline transport pilot, flight instructor, commercial pilot
- Ratings: multi-engine land; multi-engine sea; single-engine land; single-engine sea; instructor: airplane multi-engine; instructor: airplane single-engine; instrument: airplane; instrument: helicopter; rotorcraft: balloon; rotorcraft: helicopter
- Flight time: 8,500 hours in all; 15 in this make and model; 15 in the last 90 days; 15 in the last 30 days; 7,500 as pilot in command; 1,500 on instruments
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 7,445 hours
- Last inspection: 100-hour inspection, November 21, 1984; 11 hours since
- Maximum gross weight: 8,000 lb
- Seats: 3
- Landing gear: fixed
- Engine: P&W PT-6A-135 (turboprop); 0 hours total
The flight
- Departed from: BFI Seattle WA at 6:32 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 030° at 3 knots
- Visibility: 60 statute miles
- Sky: broken clouds at 10,000 ft; not recorded at 10,000 ft
- Temperature: 25°F (-4°C), dew point 18°F (-8°C)
- Altimeter: 30.00 inHg
- Observation at 6:45 pm from BFI, 5 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 1 | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.