WPR18LA196 · Cassutt IIIM
Cassutt IIIM · Accident: loss of engine power (partial) during initial climb
From Rosamond Skypark Airport (L00) to Rosamond Skypark Airport (L00)
Event
- NTSB case
- WPR18LA196
- 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
Cassutt IIIM
- Aircraft type
- Cassutt IIIM
- 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
- N43SJ
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Rosamond Skypark Airport (L00), Rosamond, CATo Rosamond Skypark Airport (L00), Rosamond, CA
- Aircraft age
- About 45 years (built 1973)
- 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
- 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
Cause areas
- Aircraft › Aircraft oper/perf/capability
- Personnel issues › Task performance
Approximate · Coordinates from the NTSB case API, not marked as estimated; no uncertainty radius is established.
NTSB narrative
The pilot was departing in his experimental, amateur-built airplane configured for aerial racing. He reported that when the airplane entered its initial climb and was about 50 ft above ground level, the engine performance reduced by about 300 rpm. The pilot attempted to continue the takeoff to complete a circuit in the airport traffic pattern. A witness saw the airplane turn left, and the nose immediately dropped and impacted the ground, followed by the right side of the airplane. The airplane sustained substantial damage to the forward fuselage and right wing. It is likely that, while the pilot was maneuvering at low altitude after the partial loss of engine power, he failed to maintain adequate airspeed, which resulted in the airplane exceeding its critical angle of attack and a subsequent accelerated stall. Postaccident examination of the engine and most of the accessories did not reveal any preimpact mechanical anomalies. However, a teardown of the carburetor showed multiple discrepancies, the most notable of which was a loose primary venturi. This condition is likely to have caused the partial loss of engine power during takeoff due to the delivery of inconsistent vacuum pressure and a disruption in fuel flow. An airworthiness directive (AD) issued 20 years before the accident required that the venturi be inspected at each annual, 100-hour, or conditional inspection. It is unknown if this AD was complied with, as the pilot/owner did not possess any records that showed the carburetor's maintenance history.
Probable cause
The pilot's failure to maintain adequate airspeed during a low-altitude maneuver after a partial loss of engine power, which resulted in exceedance of the airplane’s critical angle of attack and a subsequent accelerated stall. Contributing to the accident was a loose primary venturi in the carburetor due to improper maintenance, which resulted in a disruption in fuel flow and the subsequent partial loss of engine power.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR18LA196
- Event ID
- 20180714X41944
- Case number
- WPR18LA196
- 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, 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: 88c4c9eb0341dff0708b42f85554857318b8972efb9c99706ef17d7a74783da8; retrieved 2026-09-16T07:51:30.000Z.