Cessna 177B accident near Guthrie, Oklahoma, July 17, 1985
On July 17, 1985 at about 12:00 pm local time, a Cessna 177B, registered N20164, was destroyed in an accident near Guthrie, Oklahoma. It was an aerial observation flight under general aviation rules (Part 91). 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
- July 17, 1985 · about 12:00 pm local time
- Place
- Guthrie, Oklahoma · map
- Type
- Accident
- Injuries
- 2 people had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 177B · all 177Bs on the register
- Registration
- N20164 · no longer on the register · serial 1702638
- Damage
- Destroyed
- Flight
- Aerial observation flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE PLT STATED HE LOST ENG POWER SHORTLY AFTER TAKEOFF AND DURING INITIAL CLIMB. HE ELECTED TO GO INTO THE TREES DUE TO LACK OF ALTITUDE TO ALLOW A MORE SUITABLE LANDING AREA. AN ENG EXAMINATION DISCLOSED THAT THE NO. FOUR EXHAUST VALVE WAS STUCK OPEN DUE TO A CARBON BUILD UP ON THE ROUGH SURFACE INSIDE THE VALVE GUIDE.
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: multi-engine land; single-engine land
- Flight time: 834 hours in all; 367 in this make and model; 345 in the last 90 days; 569 as pilot in command
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Last inspection: annual inspection, February 22, 1985; 441 hours since
- Maximum gross weight: 2,500 lb
- Seats: 4
- Landing gear: retractable
- Engine: Lycoming O-320-A1F6D (piston); 0 hours total
The flight
- Destination: E42 Spearman TX
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
- Observation at 7:00 am
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.
Other NTSB records under N20164 the same tail number, which may have belonged to a different aircraft at the time
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.