CEN12LA235 · Eurocopter SA315B
Trans Aero Eurocopter SA315B · Accident: uncontained engine failure en route
From Alva Regional Airport (KAVK) to Alva Regional Airport (KAVK)
Event
- NTSB case
- CEN12LA235
- 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
Eurocopter SA315B
- Aircraft type
- Eurocopter SA315
- Category
- Helicopter
- 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
- N929JV
- Operator
- Trans Aero
- Onboard fatalities
- Unknown
- Route
- From Alva Regional Airport (KAVK), Alva, OKTo Alva Regional Airport (KAVK), Alva, OK
- 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 133: Rotorcraft Ext. Load
- 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
- 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
- Uncontained engine 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
- Aircraft › Aircraft power plant
- Organizational issues › Support/oversight/monitoring
- Personnel issues › Action/decision
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The helicopter was flying at 300 feet above the ground with an external load when the pilot heard a loud noise from the engine and the rotor rpm began to decay. He jettisoned the load and entered an autorotation. During the flare, the helicopter's main rotor blades contacted the tail rotor drive shaft. Engine disassembly and examination revealed that the turbine casing was deeply eroded by particles that had accumulated in the casing as a result of operating in dusty environments. The erosion caused a crack to develop, and non-uniform overheating of the engine led to the partial melting of the nozzle guide vanes and the rupture of the blade tips in all three turbine stages. Uncontained debris then punctured the turbine casing and shroud. According to the helicopter's maintenance records, the helicopter had operated 68 hours past a 100-hour inspection. The erosion in the engine was likely preexisting since it had been purchased second hand. Further, the records contained no entries pertaining to compliance with the manufacturer's maintenance procedures, by either the current or previous owner, for operations in sandy environments. The current operator reported that they have since complied with the manufacturer’s procedures.
Probable cause
Failure of the current and previous operators to comply with the manufacturer's maintenance procedures for operation in sandy environments, which resulted in turbine case erosion and the subsequent uncontained engine failure.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN12LA235
- Event ID
- 20120409X21232
- Case number
- CEN12LA235
- 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: 12b864fcca3a67d81c71b39e4092935112a168c6ab7fb0b361e114222d8d1d1b; retrieved 2026-09-15T17:41:30.510Z.