Greg Biffle 911 Audio Released, Witnesses Detail Fatal Crash

TMZ Sports has obtained the 911 calls made in connection to the fatal plane crash that took the lives of Greg Biffle and his family ... with witnesses documenting the horrific scene in North Carolina last month.

Officials released five calls on Tuesday ... and among the files are several individuals on the line who sounded frantic as they asked for help at the location.

One caller said he was golfing on the nearby course when he saw the Cessna C550 plane carrying Biffle and his family crash into a tree line and move downward. He said there was then a "huge explosion."

On a separate line, an apparent Statesville Regional Airport worker had a panicked tone ... saying the facility needed to be shut down immediately.

Another airport worker said they were about 200 yards from the airplane as they made the call.

One caller said they knew there were at least two pilots and at least four passengers on board.

There has been speculation that an unsecured cargo door might have caused the crash ... although no callers mentioned seeing anything to that effect.

As we previously reported, the Dec. 18 tragedy took the lives of 55-year-old Biffle, his wife Cristina, his two children, 14-year-old Emma and 5-year-old Ryder, and three others -- Craig Wadsworth and Dennis and Jack Dutton.

The scene was captured on nearby security cameras ... showing the plane in flames as it made contact with the ground.