Cessna 172N accident near Purcell, Oklahoma, July 25, 1993
On July 25, 1993 at about 3:20 am local time, a Cessna 172N, registered N4884G, was substantially damaged in an accident near Purcell, Oklahoma. It was an instructional flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
THE LACK OF SUITABLE TERRAIN ONTO WHICH TO EXECUTE THE FORCED LANDING WHICH WAS NECCESITATED BY THE PARTIAL POWER LOSS. THE POWER LOSS WAS A RESULT OF THE FATIGUE FAILURE OF THE EXHAUST VALVE ROCKER ARM ATTACHMENT STUD. A FACTOR WAS THE NIGHT CONDITIONS.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 25, 1993 · about 3:20 am local time
- Place
- Purcell, Oklahoma · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 172N · all 172Ns on the register
- Registration
- N4884G · no longer on the register · serial 17273431
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE AIRPLANE COLLIDED WITH ROUGH TERRAIN DURING A NIGHT FORCED LANDING FOLLOWING A PARTIAL POWER LOSS. THE ACCIDENT OCCURRED DURING A NIGHT DUAL INSTRUCTIONAL FLIGHT AND THE INSTRUCTOR MADE THE FORCED LANDING. INVESTIGATION REVEALED THAT THE #3 EXHAUST VALVE ROCKER ARM ATTACHMENT STUD HAD FAILED IN FATIGUE. THE SEPARATED STUD SUBSEQUENTLY LODGED UNDER THE #3 INTAKE VALVE MECHANISM AND THE CORRESPONDING PUSH ROD WAS BENT. THE ENGINE AND SUBJECT PARTS HAD ACCUMULATED A TOTAL OF 2,903.5 HOURS.
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; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 1,300 hours in all; 200 in the last 90 days
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 2,904 hours
- Last inspection: inspection type not recorded
- Maximum gross weight: 2,150 lb
- Seats: 4
- Landing gear: fixed
- Engine: Lycoming O-320-H2AD (piston); 0 hours total
The flight
- Departed from: OUN Norman OK at 3:00 am
- Destination: GLE Gainesville TX
- Flight plan: VFR
- Runway 0
- A second pilot was aboard
Weather at the time
- Light: night, bright
- Wind: from 160° at 14 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 90°F (32°C), dew point 64°F (18°C)
- Altimeter: 29.00 inHg
- Observation at 2:56 am from OKC, 20 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 2 |
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.