Incident Overview
A pilot scheduled an airplane for an afternoon flight and was informed it was available. During the preflight walk-around inspection, the pilot did not notice that the carburetor had been removed from the engine. The carburetor had been taken off for repair, but had not been reinstalled. The engine cowling had been replaced, and the airplane was returned to its regular parking spot on the ramp. No placard was installed in or on the airplane to visually alert anyone that it was out of service.
Preflight and Start
After completing the walk-around inspection without detecting the missing carburetor, the pilot and a passenger boarded the airplane. The pilot placed the fuel selector in the BOTH position and primed the engine. When the ignition key was turned to the START position, a fire erupted.
Sequence of Events
The pilot was unaware that the carburetor was missing. The aircraft had been returned to service after maintenance, but the carburetor had been removed and not replaced. The lack of a warning placard contributed to the pilot's inability to identify the aircraft's unairworthy condition during the preflight inspection. The fire occurred immediately upon attempting to start the engine.