(Photo credit: Mike Dinovo-Imagn Images)

Two wrongful death lawsuits were filed this week in connection with the December plane crash in North Carolina that claimed the lives of former NASCAR driver Greg Biffle and six others.

Biffle, 55, was killed along with his wife, Cristina, and their two children, family friend Craig Wadsworth, and the pilots, Dennis Dutton and his son, Jack.

The Dutton estates filed the suits earlier this week, each seeking $15 million in damages, according to an ESPN story published Friday.

The lawsuits allege that Biffle, as the owner of the aircraft, was responsible for ensuring its proper maintenance. The suits claim that inadequate maintenance contributed to the Dec. 18 crash that occurred shortly after takeoff near the Statesville (N.C.) Regional Airport.

According to a preliminary report this winter from the National Transportation Safety Board, Dennis Dutton was flying the Cessna 500 Citation II and Jack Dutton was in the copilot's seat.

The report found that some of the plane's instruments stopped working and that Dennis Dutton briefly turned control over to his son before the fiery crash.

Investigators concluded that neither Biffle nor Jack Dutton held the necessary endorsement on their pilot's licenses to serve as second-in-command on that plane -- a two-pilot operation under Federal Aviation Administration rules.

The NTSB is still investigating the accident and has not released a final report.

Biffle was a longtime presence in NASCAR, winning 19 races at the Cup Series level and capturing championships in both the Truck Series (2000) and Busch Series (2002). He was also recognized for humanitarian work, including relief efforts in western North Carolina after Hurricane Helene.

--Field Level Media