Christen Industries A-1 accident near Afton, Wyoming, November 4, 1990
On November 4, 1990 at about 11:40 pm local time, a Christen Industries A-1, registered N9609G, was substantially damaged in an accident near Afton, Wyoming. It was a business flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
AN IMPROPER MAINTENANCE MODIFICATION TO DISABLE THE CARBURETOR HEAT CONTROL BY UNKNOWN PERSONNEL.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- November 4, 1990 · about 11:40 pm local time
- Place
- Afton, Wyoming · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Christen Industries A-1
- Registration
- N9609G · no longer on the register · serial 1156
- Damage
- Substantial damage
- Flight
- Business flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
DURING A CROSS COUNTRY FLIGHT, THE AIRPLANE EXPERIENCED A LOSS OF ENGINE POWER. THE PILOT INITIATED A FORCED LANDING, DURING THE LANDING ROLL, THE AIRPLANE STRUCK A DITCH AND NOSED OVER. INSPECTION OF THE ENGINE REVEALED THAT THE CARBURETOR HEAT VALVE HAD BEEN SECURED IN THE COLD OR OFF POSITION. THIS MODIFICATION DID NOT ALLOW FOR THE CARBURETOR HEAT TO BE APPLIED. AT THE TIME OF THE ENGINE FAILURE, THE AIRPLANE WAS OPERATING IN ICING CONDITIONS. THERE WERE NO OTHER MECHANICAL FAILURES OR MALFUNCTIONS 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: commercial pilot
- Ratings: single-engine land; instrument: airplane
- Flight time: 1,632 hours in all; 365 in this make and model; 154 in the last 90 days; 67 in the last 30 days; 1,632 as pilot in command
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: unk
The aircraft
- Last inspection: inspection type not recorded; 0 hours since
- Maximum gross weight: 1,800 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming O-360-C1G (piston); 0 hours total
The flight
- Departed from: BFF Scottsbluff NE at 6:22 pm
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: overcast at 5,400 ft; not recorded
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 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.