Aerofab INC LAKE LA-4-250 accident near Auburndale, Florida, December 17, 2021

The NTSB's narrative final · quoted from the NTSB record

The pilot departed from a lake near his residence, about 5 nautical miles southeast of the accident site, for a local flight. About 53 minutes after departure, the airplane overflew another lake at an altitude of about 825 ft above mean sea level. After a slight right turn, the airplane rapidly descended and impacted the water. First responders recovered floating debris and found the carcass of a turkey vulture in the debris field. During recovery of the airplane, feathers were found wrapped around the fuel cap and filler neck of the right wing fuel tank, suggestive of a bird strike. Examination of the wreckage did not reveal any pre-impact anomalies with the airplane that would have precluded normal operation. Although two witnesses reported observing potential problems with the engine, describing its noise as “struggling to develop full power” and “making a sputtering noise”, the damage to the propeller blades, which included leading edge gouging, chordwise scratch marks, and “S” bending, were consistent with the engine rotating and under power at the time of impact. No additional bird remnants or impact marks were found that would conclusively explain precisely how a bird strike (or strikes) may have led to a loss of control. However, the presence of the bird carcass in the debris field, which was located about 0.1 nautical miles southwest of where the airplane began its rapid descent, suggests that bird likely remained with the airplane after being struck by it. No remnants of the windscreen were recovered with the airplane wreckage, which suggests the possibility that a bird (or birds) may have penetrated the cockpit. Given the bird remnants found on the airplane and at the accident site, along with the wreckage examination that did not identify any pre-impact anomalies with the airplane or engine, it is likely that a bird strike led to the loss of control.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.