The NTSB has released its preliminary report of the off-airport landing of Lancair IV-P N9JE at Hilton Head.  The accident killed a jogger but left the plane’s two occupants uninjured. According to the preliminary report

Further examination of the airplane revealed that the propeller assembly separated from the crankshaft flange and was missing.

In other words, the crankshaft failed.

One wouldn’t expect a crankshaft to break absent some sort of defect. If that proves to be the case, could the manufacturer of the crankshaft be held liable to the jogger’s family?

The aircraft was built from a kit and was thus "experimental." The engine, however, was not. Rather, according to FAA records, it appears that the engine was an FAA-certified, turbocharged piston engine manufactured by Teledyne Continental Motors, a company that has had its share of lawsuits related to its engines coming apart in flightTeledyne TSIO-550-C

The General Aviation Revitalization Act, or GARA, protects aircraft engine manufacturers from liability for defective engine parts older than 18 years.

We don’t know how old the engine was in this case.  However, the Lancair builder had reportedly taken the engine from a Piper Malibu.  Piper stopped using the Teledyne Continental TSIO-520 engine in its Malibus due to reliability problems. In 1988, it switched and began installing Avco Lycoming engines instead. Thus, if it turns out that the engine was an original equipment Malibu engine, then it had to be at least 20 years old — 2 years beyond GARA’s age limit.

So is Teledyne Continental Motors off the hook, regardless of whether the jogger’s family can prove that the engine was defective

No.

There is one important but little-known exception to GARA.  Regardless of the defective part’s age, GARA doesn’t protect its manufacturer from lawsuits brought by the families of those killed on the ground.