The pilot of a single-engine experimental airplane who was seriously injured in a crash Sunday remains hospitalized in critical condition.

Family members of Keith A. Cox, 52, of Hope Mills, have said he is on a ventilator, with multiple broken bones throughout his body.

Cox suffered the injuries when his kit-built airplane crashed in a sparsely wooded area near Pinelawn Cemetery at 2:40 p.m. Sunday. He was transported by helicopter to UNC Hospitals in Chapel Hill.

The cause of the crash is still under investigation by federal authorities.

Witnesses who were first on the scene of the crash, and others who listened to the radio transmissions of Cox's desperate final moments, say he is lucky to be alive.

Evan Smits and Logan Rothermund were two of the first three to reach the scene of the crash. Both said they had noticed the plane in the air because it was flying low and appeared to be having trouble with its wings.

Smits first noticed Cox's plane and two others while driving southbound on U.S. 15-501. He said what caught his eye was that two of the planes were flying very low above the tree line.

"I almost thought they were RC (remote control)," he said.

Before the crash, Smits said the plane was "unstable" and "the wings were vibrating."

"It was obvious he didn't have complete control of the plane," Smits said.

Rothermund was heading north on U.S. 15-501 when he saw the plane and noticed immediately that something was wrong.

"The wings were in resonance," Rothermund said. "What I mean by that is they were fluttering together rapidly, and that's something they are not supposed to do."

When the plane stalled and went down, Smits said he heard a "huge crack." He said he turned his car around and headed for the area where he thought the plane had gone down.

He arrived simultaneously with two other vehicles. Smits, Rothermund and Brian Glenn raced down the hill not knowing what they would find.

Smits spotted the downed plane first. He said it was missing a wing and the engine had been separated from the aircraft. He said Cox had blood running down his face, his eyes were closed and he was moaning in pain.

"I was surprised to find him alive," Smits said. "It was very obvious he was in serious pain."

Rothermund and Glenn stayed with Cox. Smits went back up the hill to get Rothermund's wife, Lori, who is a medical technician and supervisor for a local nursing home.

"I was just trying to keep him stable," Rothermund said. "I kept telling him everything is going to be OK, that help is on the way, help is here."

'He's Down! Down! Down!'

Across the county at Gilliam-McConnell Airfield in Carthage, pilots on the ground listened in horror as Cox's plane crashed.

Roland Gilliam said three planes from an area just south of Fayetteville had flown in for lunch at his airport's Pik N Pig barbecue restaurant.

"They took off about 2:30 Sunday afternoon," Gilliam said Monday. "They hadn't changed their radio frequency. An instructor that flies out of Gray's Creek was talking to them, trying to find out what was going on so he could call 911. Some of the other guys at the airport were listening to them on the radio. They heard everything as it happened."

The base radio crackled with Cox's voice as he reported that he was struggling to keep control of his airplane.

"My wings are shaking violently," he said. "I can't control it."

At the same time, Richard Hester, who keeps his own Stearman bi-plane at the Carthage airfield, heard what he first thought was a plane having engine trouble. He looked up to see Cox's plane and realized the loud vibrating noise was coming from the aircraft's ailerons, which he could see shaking and out of control, as he told Gilliam in a telephone call.

"I am watching this thing, and the ailerons are just flipping," Hester told him. "Something had to come loose to let the ailerons do that."

A second pilot, in a yellow Cessna 172 air coupe, could be seen circling the troubled craft. Back at the airport, listeners heard the two pilots talking about the problem.

"You are going to have to go down," one said over the radio.

"I'm trying to make a road," Cox replied.

At the airfield, the room filled with tension as listeners waited in dread and hopeful silence for the next voice.

"He's going down," the Cessna pilot said.

A moment later ...

"He's down! Down! Down!"

The third pilot in the group was flying at a higher altitude, Gilliam said.

"The guy in the air coupe - I think he said his name was Wayne - was circling him as he went down," Gilliam said. "The ailerons were just flapping."

Ailerons are hinged control surfaces attached along the back edges of wings. They connect with each other so that when one goes up, the other goes down. On the "down" side, lift increases just as it decreases on the opposite side, enabling a plane to roll along its front-to-rear axis.

'Lucky to Be Alive'

Smits and Rothermund credit Wayne Taylor, the pilot of the yellow Cessna, with helping them locate Cox and the wreckage so quickly.

"We saw the yellow plane and it was circling very, very low," Smits said. "We understood that it was circling low to walk us in to where he (Cox) was."

Said Rother-mund, "The pilot of the yellow plane actually was the hero. He was the one who stayed with his buddy the whole time, flying over him so everybody could find him."

When contacted by The Pilot on Monday, Taylor declined to talk about the incident until he had spoken to federal investigators.

Cox's plane was a kit-built replica of a Curtiss P-51 fighter, Gilliam said.

"It was built by Chris Bobo, the minister at Culdee Presbyterian Church," he said. "He is a minister, but he is also an aeronautical engineer. It was a sports replica, three-quarter scale, and had a four-cylinder engine. The original P-51 had a V-12. This one was a wooden plane, built just like one of those old model airplanes with wood stringers and wood frames. I think Keith Cox bought it about a year ago."

One feature of this plane's design could point to a possible source of the mechanical failure, according to Gilliam.

"Its wings fold up, so it can be transported by trailer," he said. "You have to disconnect the aileron cables for that, and then reconnect them when the wings fold out."

Cox had flown without incident from the Fayetteville area to Carthage, and apparently took off without difficulty.

"Whatever happened, it happened in the air," Gilliam said. "I went over to look at the crash site. It looked like he went straight in. He's lucky to be alive."