Cessna T207A N323JC

Summary

On 5 May 2014 at about 19:30 local time, a Cessna T207A registered N323JC, operated by Aero-Graphics Inc, was involved in an accident near Rock Springs, Wyoming, United States. 2 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

5 May 2014 at 19:30

Classification

Accident

Location

Rock Springs, Wyoming, United States

Nearest airport

Rock Springs-Sweetwater County (RKS)

Coordinates

41.5942, -109.0653

Aircraft

Cessna T207A

Registration

N323JC

Category

Airplane

Year built

1978

Engines

1

Operator

Aero-Graphics Inc

Operating rule

Part 91: General Aviation

Purpose of flight

Business

Phase of flight

Not recorded

Route

Evanston → Rock Springs

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR14LA240

Nobody was injured.

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.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

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.

Quoted verbatim from the NTSB record.