Piper PA31 N3589X

Summary

On 21 August 2023 at about 15:48 local time, a Piper PA31 registered N3589X, operated by Marc Inc, was involved in an accident near Durant, Oklahoma, United States. One person was 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

21 August 2023 at 15:48

Classification

Accident

Location

Durant, Oklahoma, United States

Nearest airport

Durant Rgnl/Eaker Fld (DUA)

Coordinates

33.9397, -96.3951

Aircraft

Piper PA31

Registration

N3589X

Category

Airplane

Year built

1980

Engines

2

Operator

Marc Inc

Operating rule

Part 91: General Aviation

Purpose of flight

Aerial Observation

Phase of flight

Not recorded

Route

Tulsa → Durant

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CEN23LA370

Nobody was injured.

The loosening of a connecting rod cap nut for reasons that could not be determined, which resulted in a mechanical failure of the engine and an in-flight fire.

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

Read the full NTSB narrative

While in flight, the pilot heard and felt a bang from the right side of the airplane. He saw that the right engine nacelle had a hole in it and the engine was on fire. He secured the engine and diverted to a nearby airport. While on final approach for landing, the engine fire reignited. The pilot landed the airplane, taxied clear of the runway, shut down the left engine, and egressed. The engine fire continued to burn and consumed the right engine and a majority of the fuselage. Examination revealed that the right engine’s No. 2 cylinder was displaced from the engine case but remained attached via the injector manifold vent tube and injector lines. All eight of the No. 2 cylinder’s attach bolts were broken off at the case. The connecting rod cap was found lodged in the bottom of the piston. One connecting rod bolt was found broken off flush in the connecting rod; the top portion was not located. The other connecting rod bolt remained in the connecting rod cap with the nut also not located. One side of the lower connecting rod flange was bent back towards the piston, capturing the nut and remaining portion of the broken bolt. Neither bearing half could be identified in the remaining material. Numerous impact marks were noted on the piston, cylinder, and case. A review of maintenance records found that the engine was last overhauled about 4 ½ years before the accident and had accrued about 900 hours since the overhaul. Based on the available information, it is likely that the nut that secured one side of the connecting rod cap became loose, resulting the separation of the cap and subsequent damage to the No. 2 cylinder. Since the nut could not be located, the reason it did not remain secure could not be determined.

Quoted verbatim from the NTSB record.