Durham, N.C. — The callers to Durham's emergency dispatch center on Friday evening spoke in frantic, unbelieving voices: A plane had just crashed on Interstate 85.

"I'm on 85, and we are right at a sign that says, 'Welcome to the City and County of Durham,' and a private plane has just crashed," one caller said.

Durham County sheriff's deputy and longtime pilot Rick Fuller was flying a 1947 Piper J3C plane when it crashed on the shoulder of I-85 near Red Mill Road around 7 p.m.

Help came quickly.

"My husband is over there. He went over on the southbound side to go help," a 911 caller said. "And there's several cars that have stopped also."

Witnesses said they saw Fuller's plane clip some trees before it crashed, but it did not catch on fire.

"I saw it hit the trees, and it fell right behind me," a caller said.

"I saw sparks. I didn't see any flames," reported another 911 caller.

Fuller's plane came from the nearby Lake Ridge Aero Park, whose 3,200-foot grass landing strip comes close to the interstate. Friends said he was following his weekly habit of practicing take-offs and landings.

That day, his plane narrowly missed dozens of cars traveling on that busy highway.

"It came right over the trees and down nose-first," a 911 caller said. "It did not hit any other cars. It just went right onto the highway."

Fuller was transported to UNC Hospitals in Chapel Hill where he had been upgraded to fair condition Monday, but he was again listed in critical condition Tuesday, a nurse supervisor said.

His plane was the only vehicle damaged in the crash.

Randy Smith, the co-owner of the Lake Ridge airport, said the Piper had passed its annual inspection by a government-certified mechanic.

The Federal Aviation Administration has taken the plane and will examine the wreckage as part of its crash investigation.