ERA13LA174 · Piper PA-25-235
Aerial Banners Piper PA-25-235 · Accident: loss of engine power (total) en route
From Northwest Florida Beaches International Airport (ECP) to Northwest Florida Beaches International Airport (ECP)
Event
- NTSB case
- ERA13LA174
- 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-25-235
- Aircraft type
- Piper PA-25
- 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
- N86AB
- Operator
- Aerial Banners
- Onboard fatalities
- Unknown
- Route
- From Northwest Florida Beaches International Airport (ECP), Panama City, FLTo Northwest Florida Beaches International Airport (ECP), Panama City, FL
- Aircraft age
- About 48 years (built 1965)
- 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
- Defining eventThe 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
- Loss of engine power (total)
- 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
- Aircraft › Aircraft power plant
- Not determined › Not determined
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot departed and picked up an aerial advertising banner for a local flight. About 6 minutes later, the airplane's engine suddenly lost all power. The pilot unsuccessfully attempted to troubleshoot the loss of engine power, jettisoned the banner at an altitude of about 500 feet, and performed a forced landing to a pine forest below, which resulted in substantial damage to the airplane. Postaccident examination of the engine revealed that the crankshaft gear alignment dowel had sheared and that the gear had rotated from its normal position. The gear's attaching hardware remained installed and undamaged. Detailed examination of the gear and alignment dowel showed that their hardness was consistent with that required by the design and that they were within or nearly within nominal dimensional tolerances described by the manufacturer. The counter-bored pilot hole at the aft of the crankshaft where the gear was seated was between 0.0008 and 0.0013-inch oversized. There were no discrepancies found with the retaining bolt, and it could be threaded into the crankshaft with minimal resistance. A definitive cause for the loss of preload to the crankshaft gear attaching bolt could not be determined during the engine examination.
Review of maintenance records showed that the engine had been installed onto the accident airplane following an overhaul, which was originally precipitated by a propeller strike. The records provided that documented the overhaul and returned the airplane/engine to service lacked language specifying compliance with a manufacturer service bulletin that provided explicit instructions for the installation of the crankshaft gear to the crankshaft; however, the provided records did document part numbers and torque values consistent with those specified by the service bulletin.
Probable cause
A loss of preload to the crankshaft gear attachment bolt, resulting in rotation of the crankshaft gear and a subsequent total loss of engine power. The root cause for the loss of preload could not be determined during a postaccident examination of the components.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ERA13LA174
- Event ID
- 20130318X82854
- Case number
- ERA13LA174
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
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. 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: afb90a1b3183c45d3949a7e01f8a53eeda7b985a308b699d6aadb976e3f33c4f; retrieved 2026-09-15T21:07:48.138Z.