Cessna T207A accident near Rock Springs, Wyoming, May 5, 2014
On May 5, 2014 at about 7:30 pm local time, a 1978 Cessna T207A, registered N323JC, was substantially damaged in an accident during enroute (descent) near Rock Springs, Wyoming (Rock Springs-Sweetwater County airport). It was a business 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
Maintenance personnel’s application of insufficient torque to the engine cylinder through bolts during replacement of the No. 1 cylinder, which resulted in the displacement of the No. 2 main bearing, the bearing shifting, and a catastrophic engine failure.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 5, 2014 · about 7:30 pm local time
- Place
- Rock Springs, Wyoming · Rock Springs-Sweetwater County · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna T207A A, built 1978 · all T207As on the register
- Registration
- N323JC · no longer on the register · serial 20700494
- Damage
- Substantial damage
- Flight
- Business flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The commercial pilot reported that, during the business flight, while about 9,500 ft mean sea level, the engine lost all power. The pilot was unable to restart the engine and realized that the airplane would not be able to reach the airport, so he initiated a forced landing in a nearby clearing. Examination of the engine revealed that the No. 2 main bearing had separated from the bearing support. The No. 2 main bearing support exhibited evidence of bearing shift. The No. 2 main bearing support mating surfaces displayed fretting damage, consistent with the application of insufficient torque on the cylinder through bolts. Further, the breakaway torque on the Nos. 1 and 2 cylinder through bolts were below specifications. It is likely that the insufficient torque on the Nos. 1 and 2 through bolts resulted in the fretting damage, the No. 2 main bearing shifting, and the subsequent separation of the crankshaft. Further examination of the engine revealed that the No. 2 cylinder piston was labeled as a piston for a naturally aspirated engine, whereas the other pistons were labeled for a turbocharged engine, which the airplane was equipped with. No additional anomalies were observed with the airframe and engine that would have precluded normal operation. A review of maintenance records revealed that the No. 1 cylinder was replaced 94.5 hours before the accident, which would have required the removal and installation of the Nos. 1 and 2 cylinder through bolts. It is likely that maintenance personnel applied insufficient torque on the Nos. 1 and 2 cylinder through bolts during the reinstallation of the No. 1 cylinder.
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
What happened, in order
- Loss of engine power (total) during enroute (descent) defining event
- Off-field or emergency landing during emergency descent
The NTSB's findings
- cause Personnel issues › Task performance › Maintenance › Replacement › Maintenance personnel
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip engine power section › Failure
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng cyl section › Incorrect service/maintenance
Pilot
- Certificate: commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 5,797 hours in all; 453 in this make and model; 241 in the last 90 days; 88 in the last 30 days; 5,585 as pilot in command
- Last flight review: April 22, 2014
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: left
- Injury: no injuries
Passenger
- Seat: rgt
- Injury: no injuries
The aircraft
- Airframe total time: 9,330 hours
- Last inspection: annual inspection, January 17, 2014
- Maximum gross weight: 3,803 lb
- Seats: 3
- Landing gear: fixed
- Engine: Continental TSIO-520-M (turboprop); 4,811 hours total
- Operator: Aero-Graphics INC
The flight
- Departed from: EVW Evanston WY at 6:00 pm
- Destination: RKS Rock Springs WY
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 290° at 9 knots, gusting 17
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 68°F (20°C), dew point 10°F (-12°C)
- Altimeter: 29.86 inHg
- Observation at 7:30 pm from RKS, 15 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight 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.
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.