Amateur-built 4 accident near Mansfield, Washington, June 4, 1989
On June 4, 1989 at about 8:15 pm local time, a amateur-built 4, registered N5321U, was destroyed in an accident near Mansfield, Washington. It was a personal flight under general aviation rules (Part 91). 2 people were killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
FAILURE OF THE LEFT WING MAIN SPAR DUE TO OVERLOAD FOR UNDETERMINED REASONS.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 4, 1989 · about 8:15 pm local time
- Place
- Mansfield, Washington · map
- Type
- Accident
- Injuries
- 2 people were killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built 4
- Registration
- N5321U · registry record · serial 7-12
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE LEFT WING OF THE HOMEBUILT SEPARATED IN FLIGHT. THE WING MAIN SPAR WAS A HEAVY WOODEN BEAM WITH METAL REINFORCEMENT PLATES BOLTED TO THE FORE AND AFT SURFACES THAT EXTENDED THROUGH THE AIRCRAFT CABIN. THE SPAR WAS FOUND BROKEN ADJACENT TO THE LEFT SIDE OF THE CABIN, THROUGH BOLT HOLES AT THE METAL REINFORCEMENT BRACKETS. THE WOOD SPLINTERS IN THE FRACTURED SPAR WERE BENT TOWARD THE TOP SURFACE OF THE WING. THERE WAS NO EVIDENCE OF FATIGUE CRACKING OR DRY ROTTING.
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: commercial pilot
- Ratings: single-engine land; single-engine sea
- Flight time: 1,009 hours in all
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Last inspection: inspection type not recorded
- Maximum gross weight: 1,657 lb
- Seats: 2
- Landing gear: fixed
- Engine: Gm CORVAIR 110 (piston); 0 hours total
The flight
- Departed from: S35 Okanogan WA at 7:45 pm
- Destination: WA97 Buena WA
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 270° at 13 knots
- Visibility: 30 statute miles
- Sky: clear
- Temperature: 82°F (28°C), dew point 45°F (7°C)
- Altimeter: 30.00 inHg
- Observation at 7:55 pm from EAT, 36 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 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.