Cessna 421C accident near Idaho Falls, Idaho, November 16, 1985
On November 16, 1985 at about 9:45 pm local time, a Cessna 421C, registered N124RS, was substantially damaged in an accident near Idaho Falls, Idaho (Idaho Falls airport). It was an executive or corporate flight under general aviation rules (Part 91). No one was hurt; 5 people were on board or involved. The weather was instrument conditions (cloud, fog or low visibility).
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
- November 16, 1985 · about 9:45 pm local time
- Place
- Idaho Falls, Idaho · Idaho Falls · map
- Type
- Accident
- Injuries
- No one was hurt; 5 people were on board or involved.
- Weather
- instrument conditions (cloud, fog or low visibility)
- Aircraft
- Cessna 421C · all 421Cs on the register
- Registration
- N124RS · registry record · serial 421C0673
- Damage
- Substantial damage
- Flight
- Executive or corporate flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
DURING INITIAL APCH INFLIGHT ICING WAS ENCOUNTERED. THE WINDSCREEN FAILED TO HEAT DUE TO AN INOPERATIVE INVERTER. A SMALL AREA ON THE RIGHT BOTTOM PORTION OF THE WINDSCREEN DE-ICED DUE TO DEFROST HEAT. THE PLT ELECTED TO LAND USING THE SMALL CLEAR AREA OF THE WINDSCREEN FOR OUTSIDE REFERENCE. A HARD LANDING RESULTED FROM A LOSS OF DEPTH PERCEPTION.
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: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane single-engine; instrument: airplane
- Flight time: 2,675 hours in all; 180 in this make and model; 75 in the last 90 days; 2,500 as pilot in command
- Medical certificate: Class 1 (invalid medical for flight)
- Seat: left
The aircraft
- Airframe total time: 1,170 hours
- Last inspection: annual inspection, April 1, 1985; 30 hours since
- Maximum gross weight: 6,822 lb
- Seats: 8
- Landing gear: retractable
- Engine: Continental GTSIO-520-L (piston); 0 hours total
The flight
- Departed from: BFI Seattle WA at 7:30 pm
- Destination: IDA Idaho Falls ID
- Flight plan: IFR
- Runway 20, 9,000 ft by 150 ft
Weather at the time
- Light: daylight
- Visibility: 1 statute miles
- Sky: not recorded
- Temperature: 28°F (-2°C), dew point 25°F (-4°C)
- Altimeter: 30.00 inHg
- Observation at 9:53 pm from IDA
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 4 |
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.