Families of Two Men Killed in RV-8 Engine Failure Win $5 Million From Superior Air Parts

On March 12, 2016, Dane Sheahen and James Kos took off from Spruce Creek Airport in Port Orange, Florida, bound for Winter Haven Regional Airport roughly 100 miles to the southwest. Sheahen, 63, had built the Van's RV-8A experimental aircraft himself using a kit that included a Superior Air Parts XP-400 engine. The engine had logged only about 20 hours since installation.

About 30 miles short of Winter Haven, the crankshaft inside the XP-400 broke. Power vanished, the plane went down near Clermont, and both men died. Sheahen was an Illinois hardware store owner and licensed pilot. Kos, 57, was a retired construction worker from Oklahoma. Their families were left to find out why an engine with almost no time on it had come apart.

The families retained Ladd Sanger of Slack Davis Sanger, who filed suit in 2018 in Dallas County District Court against Superior Air Parts, based in Coppell, Texas, and against Ruhrtaler Gesenkschmiede F.W. Wengeler GmbH, the German manufacturer that forged the crankshaft. Aviation experts retained for the case found no obvious metallurgical flaws in the part itself. Instead, the evidence pointed to the engine's design: detonation issues created abnormal stress cycles that a properly validated crankshaft should have been engineered to survive. Sanger argued publicly that Superior had released the XP-400 to market without adequate testing.

Separately, the National Transportation Safety Board documented 'extensive beach markings and a finely-textured surface indicative of fatigue progression' originating near the connecting rod journal, consistent with crack growth from a subsurface location over many load cycles.

In February 2020, Superior settled for $5 million, split between both families. Ruhrtaler separately paid $50,000 to the Kos estate, bringing total recovery to $5.05 million. The settlement was not sealed; the Kos family asked that it be made public. By that point, Superior had already ceased XP-400 and XP-382 sales in March 2019 and initiated a mandatory buyback of all units previously sold. The FAA also proposed an airworthiness directive in January 2020 targeting approximately 115 potentially defective crankshafts in other Superior engine models.