TULSA, Oklahoma - Green Country is mourning the loss of a local aviation expert whose passion made flying safer for us all.

Randy Harris, 55, lost his life last week when the stunt plane he was flying crashed. Harris was doing stunts in his Skybolt 300 with active U.S. Air Force Lt. Dale Shillington, 25, while preparing for the Vance Air Show.

A witness told NTSB investigators they saw the Skybolt 300 stunt plane -- one Harris built by hand -- doing barrel rolls before it disappeared below a tree.

Both Harris and Shillington died in the crash.

Friends and family gathered at the Tulsa Air and Space Museum to remember him on Saturday.

7/27/2016 Related Story: Witness: Plane Was In Inverted Spin Just Before Deadly Crash Near Enid

Harris was a flight test engineer - most recently for American Airlines – and worked on a lot of programs that helped make commercial flights safer.

Friends say he had a thrill for aviation from an early age and that his stunt shows were second to none. 

But within the local aviation community, he was known for being the go-to guy for help and troubleshooting.

"He was constantly engineering things," Tim Albin said. "He was constantly looking at things to make them better, safer, faster, more efficient. You'd be hard-pressed to find a small airplane probably within a 100 miles of Tulsa, Oklahoma, that he didn't help somebody either build or one of this modifications is on, or he showed somebody how to fix something on those aircraft."

He even designed the supports that hold up a retired MD-80 jet displayed outside the Tulsa Air and Space Museum.

Randy was known and well respected for his innovation and the stunts he performed at shows - his love of flying only surpassed by one thing.

"The only thing he loved more than flying was his wife Linda," Albin said.

The couple were married for 25 years.

After the funeral Saturday, a group of T-6s flew over in the 'Missing Man' formation - with one plane breaking away and heading west into the sun, paying respect to a fellow airman.

The NTSB still is investigating the cause of the crash. 

"His life has probably touched tens of thousands of passengers that have flown," Albin said.