What sounded like a scream was heard over the radio. Within five minutes, air traffic controllers had lost all contact with a pilot and a flight instructor aboard the turboprop plane that had been 15,000 feet above McClellanville.

Minutes later, someone reported seeing a plane plummeting into the woods of the Francis Marion National Forest.

In the 10 minutes the plane spent in the air, something had gone terribly wrong.

When investigators found the wreckage, twisted metal and tree branches spanned 290 feet in a swamp, along with the bodies of the two men on board.

These final moments and other details about the fatal plane crash in June were released this month in a report by the National Transportation Safety Board, the agency investigating the crash.

The report details information about the flight, the aircraft, the wreck, the pilots' medical and flight backgrounds and other details that will be used to determine what caused the plane to crash.

The final report is expected to be released in the next three months, but a nine-page report released March 6 provides further insight into the accident that killed 44-year-old Patrick Eudy, of Mount Pleasant, and instructor Robert Ulrich, 69, of Bellevue, Idaho, on June 20.

Flight experience

It was the first time in the air together for Eudy and Ulrich, according to the report. Ulrich was a flight instructor and Eudy was trying to get recertified on flying the plane he owned, a 1977 Rockwell International 690B.

It was supposed to be a routine flight.

Eudy, president and CEO of the Matthews, N.C.-based telecommunications firm American Broadband, had spent more than 1,500 hours in the air as a pilot, according to the NTSB report.

It remains unclear how many times he had flown the eight-seat Rockwell that friends say he had owned for three or four years.

Ulrich had spent more than 22,000 hours in flight, including 75 hours in the six months before the crash, according to the NTSB reports. Nearly 20 percent of the time Ulrich spent in the air was as a flight instructor, the reports stated.

Ulrich had been issued a Restricted Medical Certificate after losing an eye to an injury, but his Federal Aviation Authority medical exam showed he had 20/20 vision in his remaining eye.

Ulrich also suffered from diabetes, according to the report, but the report does not indicate if his or Eudy's health played any part in the crash. Eudy and Ulrich tested negative for drugs and alcohol, according to the forensic toxicology results listed in the NTSB report.

The flight

Eudy and Ulrich departed from the Charleston Executive Airport on Johns Island at 4:29 p.m.

Either Eudy or Ulrich told air traffic control they wanted to do some air work and asked to fly at about 15,000 feet, according to a transcript of the audio recordings between the plane and air traffic.

About 15 minutes later, one of the pilots said they were doing 360-degree turns at about 14,000 feet and were going to be doing that for another 10 minutes, according to the transcript.

A map based on radar data indicates the plane did two 360 turns, the first to the right and the second to the left.

A few seconds into the second turn, one of the pilots said "thank you, sir" to air traffic control, which had approved the request to spend another 10 minutes doing turns.

That was the last recorded transmission known from the plane.

Air traffic control attempted to contact Eudy and Ulrich, but there was no answer and the plane disappeared from the radar, the report stated.

On the ground, a witness saw the plane doing the two 360-degree turns, then saw the plane abruptly turn right while starting to lose altitude, according to the report.

Radar showed the plane crossed U.S. Highway 17 at 12,100 feet.

Less than two minutes later, a loud background noise, which lasted for about seven seconds, along with a single voice making a sound similar to "ahhh" was heard on the radio, according to the transcript, but aviation officials could not determine what plane it came from.

Within seconds, a witness saw the plane turn left while dropping another 7,500 feet within 28 seconds.

A witness said the nose was "completely vertical down" before the propellers ripped through the trees of the forest and crashed into the swamp, according to the report.

The plane did not catch fire before, during or after impact, the report stated.

When first responders arrived, the smell of jet fuel filled the air.

The coroner later determined that Ulrich and Eudy died of full body blunt force trauma.

The plane

The twin-engine plane had been inspected three months before the crash, and the plane's two engines appeared to be working at the time the plane crashed, according to the findings by NTSB.

No problems were found with the propellers' assembly that could have led to a malfunction. Both propellers were missing a piece called the spinner, but NTSB did not indicate whether that occurred before or after the crash.

While the report appears to rule out certain possibilities for the cause of the crash and describes how the plane went down, it does not yet show why it went down.

NTSB officials said their final report detailing the cause of a crash is usually published one year after an incident.

Reach Natalie Caula Hauff at 937-5594 or Twitter.com/ncaula.