Approach and Engine Issues
Witnesses observed the aircraft flying toward the airport with engines that were "running rough, cutting out, or backfiring and sputtering." As the airplane made its landing approach, it was described as "high and extremely fast." One engine was windmilling, while the other engine was reported to be "running OK." Shortly after, witnesses heard an engine "spool up for a go-around."
Loss of Control and Impact
The airplane was seen to bank left about 80 degrees. At an altitude of approximately 100 to 150 feet, the tail appeared to slip to the right, and the plane banked further left and went inverted. The aircraft struck a building while inverted and pointing slightly to the left. A post-impact fire ensued, destroying the airplane and substantially damaging the building.
Engine and Propeller Examination
Both engines were disassembled and inspected. The only discrepancies noted were carbon-fouling of the top and bottom spark plugs from cylinders 1 and 6 on the left engine. Disassembly of both propellers revealed that the left propeller "did not have power and was not feathered." The right propeller "was operating at moderate or high power."
Investigation Details
No further information regarding the aircraft type, registration, operator, location, date, occupants, injuries, or fatalities was provided in the source. The investigation focused on the physical evidence from the engines and propellers, as well as witness accounts.