Piper PA-23-250 N62BA

Summary

On 6 September 2007 at about 22:00 local time, a Piper PA-23-250 registered N62BA was involved in an accident near Bernardsville, New Jersey, 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

6 September 2007 at 22:00

Classification

Accident

Location

Bernardsville, New Jersey, United States

Coordinates

40.7450, -74.5567

Aircraft

Piper PA-23-250

Registration

N62BA

Category

Airplane

Engines

2

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Positioning

Phase of flight

Not recorded

Route

Philadelphia → Newburgh

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

NYC07LA221

Nobody was injured.

The failure by unidentified maintenance personnel to follow appropriate procedures when attaching the No. 3 cylinder, which was replaced subsequent to the engine overhaul and not entered in the logbook, resulting in fatigue failures of the cylinder studs.

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

Read the full NTSB narrative

About 25 minutes into the positioning flight, the pilot felt a slight vibration and a few minutes later noticed a small streak of smoke trailing along the right engine cowling. He shut down the right engine as a precautionary measure. He then observed a flame emanating from the right side of the engine, so he pitched the nose of the airplane down, increasing the airspeed and extinguishing the fire almost immediately. He subsequently landed uneventfully. Examination of the right engine revealed that the number 3 cylinder was separated from the engine case, and that the right wing was substantially damaged. Detailed examination of the number 3 cylinder attachment studs revealed that they had failed in fatigue, most likely due to insufficient preload of the fastening nuts. Paint in the nut contact area around one of the cylinder hold down plates was present, and was not disturbed. Adequate friction during the attachment and torquing process would be expected to disturb and remove the paint layer, as was seen at other locations on the hold down plate. Further, the paint observed between the cylinder flange and hold down plate was not the primer specified by the engine manufacturer's overhaul manual, and was applied at a thickness greater than that specified in the manual. The presence of this paint could have lead to an in-service loss of preload, even if sufficient torque was applied to the cylinder nuts at the time of installation. Although logbook records had no entries to show that any of the right engine’s cylinders had been removed or replaced since the last engine overhaul, evidence indicated that the No. 3 cylinder had been replaced after the engine was overhauled. According to Federal Aviation Administration records, the cylinders installed during the overhaul were new, and had serial and cylinder class numbers stamped on them. The overhauler stated that new cylinders were received with a thin coat of zinc chromate, and that the engine was painted after reassembly. The failed No. 3 cylinder examined after the accident did not have serial numbers, and had paint between the cylinder flange and hold down plate. Logbook records had no entries to show any of the right engine's cylinders had been removed or replaced since the last engine overhaul.

Quoted verbatim from the NTSB record.