WPR12LA356 · Rockwell S2R
Royal Flying Service Rockwell S2R · Accident: loss of engine power (partial) during initial climb
From 8WA · Royal City, WA to 8WA · Royal City, WA
Narrative check · The NTSB narrative appears to contradict this record's damage. Values are shown as recorded, not corrected; compare with the narrative.
Event
- NTSB case
- WPR12LA356
- 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
Rockwell S2R
- Aircraft type
- Rockwell S2
- 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
- N8468V
- Operator
- Royal Flying Service
- Onboard fatalities
- Unknown
- Route
- From 8WA · Royal City, WATo 8WA · Royal City, WA
- 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 137: Agricultural
- 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
- Initial climb
- 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 (partial)
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial Possible conflict
Cause areas
- Aircraft › Aircraft power plant
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot stated that shortly after taking off for the aerial application flight the engine began to run rough. Because he could not maintain altitude and was concerned about clearing a set of power lines in front of him, the pilot partially dumped the airplane’s aerial application load. After the airplane cleared the power lines, the pilot attempted to land on a road; however, during the touchdown the airplane veered off of the road and into a ditch. A postaccident fire consumed the airplane. A postaccident examination of the engine revealed that the No. 2 cylinder exhaust rocker boss housing had separated from the cylinder, which prevented the cylinder's exhaust valve from opening and resulted in the loss of engine power. Maintenance records revealed that the cylinder had been inspected in accordance with the time interval specified by the applicable Federal Aviation Administration airworthiness directive (AD). The AD specifies a 100-hour recurring inspection requirement; the engine had accumulated 91 hours since its last inspection.
Probable cause
The loss of engine power due to the separation of the No. 2 cylinder exhaust rocker boss housing, which prevented the exhaust valve from opening.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR12LA356
- Event ID
- 20120814X10320
- Case number
- WPR12LA356
- 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: 697dab8c6316bef2044f1a18a00a8967cb6ed6ddb58bfda1f4f07a0a228c9730; retrieved 2026-09-15T19:19:47.872Z.