NYC07LA221 · Piper PA-23-250
Piper PA-23-250 · Accident: partial loss of engine power (mechanical failure) en route
From Northeast Philadelphia Airport (PNE) to New York Stewart International Airport (SWF)
Event
- NTSB case
- NYC07LA221
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Piper PA-23-250
- Aircraft type
- Piper PA-23
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N62BA
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Northeast Philadelphia Airport (PNE), Philadelphia, PATo New York Stewart International Airport (SWF), Newburgh, NY
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · cruise
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Partial loss of engine power (mechanical failure)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Other maintenance personnel › Procedures/directives, not followed
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
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.
Probable cause
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.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record NYC07LA221
- Event ID
- 20070926X01447
- Case number
- NYC07LA221
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, coordinates. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 1c83bfdb20f4d3e066443d1223e2f36781bd2f2eca6952e018d6d467809de5d0; retrieved 2026-09-22T03:27:00.834Z.