Aero Commander 690A accident near Ryderwood, Washington, December 1, 1990
On December 1, 1990 at about 2:41 am local time, a Aero Commander 690A, registered N400N, was destroyed in an accident near Ryderwood, Washington. It was a personal flight under general aviation rules (Part 91). 5 people were killed and 1 person was seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
THE PILOT'S IMPROPER INFLIGHT PLANNING AND FAILURE TO MAINTAIN PROPER ALTITUDE IN MOUNTAINOUS TERRAIN AT NIGHT.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- December 1, 1990 · about 2:41 am local time
- Place
- Ryderwood, Washington · map
- Type
- Accident
- Injuries
- 5 people were killed and 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Aero Commander 690A · all 690As on the register
- Registration
- N400N · no longer on the register · serial 11156
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
AS THE FLT WAS APCHG THE DESTN, AT NGT, THE PLT OBTAINED VECTORS FOR A DSCNT OVER MOUNTAINOUS TERRAIN. DURING THE APCH, HE CANCELLED THE IFR FLT PLAN & THE ACFT DSNDD BELOW RADAR COVERAGE. SUBSEQUENTLY, THE ACFT CRASHED IN MOUNTAINOUS TERRAIN, NORTHWEST OF THE DESTN ARPT. IMPACT OCCURRED IN A WOODED AREA AT AN ELEVATION OF ABOUT 2700 FT. THE ELT DID NOT ACTIVATE DURING THE ACDNT. A SEARCH WAS INITIATED ON 12/1/90, BUT THE ACFT & SURVIVING PASSENGER WERE NOT FND UNTIL THE NEXT DAY. THE CANADIAN ATP PLT & OTHER 4 PASSENGERS WERE FATALLY INJURED. AFTER INITIAL IMPACT WITH TREES, THE MAIN PORTION OF THE FUSELAGE TRAVELED ABOUT 1000 FT BEFORE COMING TO REST. NO PREIMPACT MECHANICAL PROBLEM WAS FOUND.
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, commercial pilot
- Ratings: multi-engine land; multi-engine sea; single-engine land; single-engine sea; instrument: airplane
- Flight time: 11,714 hours in all; 2,647 in this make and model; 51 in the last 90 days; 22 in the last 30 days; 10,976 as pilot in command
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: unk
The aircraft
- Last inspection: inspection type not recorded; 0 hours since
- Maximum gross weight: 10,250 lb
- Seats: 7
- Landing gear: retractable
- Engine: Garrett TPE-331 (turboprop); 0 hours total
- Operator: Aero Air
The flight
- Destination: KLS Kelso WA
- Flight plan: IFR
- Runway 0
Weather at the time
- Light: night, dark
- Visibility: 10 statute miles
- Sky: broken clouds at 1,200 ft; not recorded
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
- Altimeter: 30.00 inHg
- Observation at 2:34 am from KLS, 16 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 4 | 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.