SEA86LA208 · Curtiss JN4-D
Curtiss JN4-D · Accident: partial loss of engine power (mechanical failure) during initial climb
Event
- NTSB case
- SEA86LA208
- 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
- 0
- 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
Curtiss JN4-D
- Aircraft type
- Curtiss JN4
- 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
- N511JN
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From not recordedTo not recorded
- 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
- Initial climb
- 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
- Fuel system, carburetor › Cracked
- Fuel system, carburetor › Improper
- Pilot in command › Proper descent rate, not possible
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
THE PLT REPORTED A NORMAL TAKEOFF WAS MADE WITH 1300 RPM. AT LIFTOFF A SMALL AMOUNT OF BLACK SMOKE EMITTED FROM BOTH EXHAUST STACKS AND THE RPM DROPPED TO 1250. AFTER CLEARING THE RWY, MORE BLACK SMOKE EMITTED AND THE RPM DROPPED TO 1200. THE PLT CLEARED TWO 40 FOOT TALL TREES AT THE END OF THE RWY AND MADE A HARD LANDING IN A FIELD BEYOND THE TREES. INVESTIGATION DISCLOSED THE FLOAT FROM THE ZENITH CARBURETOR HAD 17 VERITCAL LINES ON THE OUTSIDE DIAMETER AND CRACKS. THE FLOAT WAS FUEL SATURATED.
Verbatim NTSB analysis from the NTSB dataset
Sources
NTSB record SEA86LA208
- Event ID
- 20001213X34644
- Case number
- SEA86LA208
- 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. 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: b835c0ac39d2016c5227d3cb56c7a949325570ee549537550ef47104525abb7a; retrieved 2026-09-22T01:15:40.237Z.