Beechcraft A36 N3241N

Summary

On 12 December 2015 at about 00:31 local time, a Beechcraft A36 registered N3241N was involved in an accident near Fayetteville, North Carolina, United States. 4 people were on board and one was seriously injured, 3 had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

12 December 2015 at 00:31

Classification

Accident

Location

Fayetteville, North Carolina, United States

Coordinates

34.9900, -78.8297

Aircraft

Beechcraft A36

Registration

N3241N

Category

Airplane

Year built

1999

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Stevensville → Charleston

Aircraft damage

Substantial

Weather

VMC

Light

Night

NTSB number

ERA16LA066

1 person was seriously injured.

Maintenance personnel's application of an unapproved sealant to the engine case halves during engine overhaul, contrary to manufacturer's instructions, which resulted in lubrication restriction due to a bearing shift and the subsequent internal failure of the engine due to the loss of case through-bolt torque.

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

Read the full NTSB narrative

During a cross-country flight at night, the airplane experienced a total loss of engine power. The private pilot's attempts to restart the engine were unsuccessful. The pilot attempted to glide the airplane to a diversionary airport, but when he realized the airplane would not reach the airport, he conducted a forced landing into wooded terrain. Teardown examination of the engine revealed that the No. 1 cylinder and No. 3 connecting rod had fractured. Metallurgical examination revealed that there was a gray rubbery substance on the case halves, through bolts, and main bearing saddle faces, which could have restricted oil flow. The engine manufacturer's overhaul manual and a service bulletin and service information letter (SIL) listed only one approved sealant for use between case halves, which was similar in color and texture to grape jelly not to the rubbery gray sealant found in the engine, which was not an approved sealant. Further, the SIL stated that the use of an incorrect sealant "on mating threads and between mating surfaces can cause incorrect torque application and subsequent engine damage or failure." Further, the No. 3 connecting rod journal exhibited heat damage and deformation, and the No. 3 connecting rod fracture was consistent with a lack of lubrication. Additionally, the No. 4 main bearing saddle boss exhibited fretting damage, consistent with bearing shift due to lack of torque on the through bolts and blockage of its oil port, which also would have restricted oil flow. Review of maintenance records revealed that the engine was overhauled about 20 months before the accident. The engine had been operated for about 300 hours during that time. It is likely that maintenance personnel applied the unapproved sealant to the engine case halves during the engine overhaul, which ultimately resulted in the total loss of engine power.

Quoted verbatim from the NTSB record.