Cassutt IIIM N43SJ

Summary

On 14 July 2018 at about 17:00 local time, a Cassutt IIIM registered N43SJ was involved in an accident near Rosamond, California, United States. One person was on board and one had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

14 July 2018 at 17:00

Classification

Accident

Location

Rosamond, California, United States

Nearest airport

Rosamond Skypark (L00)

Coordinates

34.8689, -118.2072

Aircraft

Cassutt IIIM

Registration

N43SJ

Category

Airplane

Year built

1973

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Rosamond → Rosamond

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

WPR18LA196

1 person had minor injuries.

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.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full 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.

Quoted verbatim from the NTSB record.