Duncan was the pilot of the Beechcraft BE-35 plane and was a National Transportation Safety Board (NTSB) employee. Gardella was a flight instructor.
The crash happened just over six miles from the Warrenton-Fauquier Airport. The National Transportation Safety Board said Tuesday that the crash happened at about 4:21 p.m. A Piper PA-28, owned and piloted by Thomas R. Proven, 70, of Broad Run, and a Beechcraft BE-35 collided midair about 30 miles north of Fredericksburg. Proven was transported by ambulance to Mary Washington Hospital and was in good condition, according to a hospital spokeswoman. Proven is a Federal Aviation Administration (FAA) employee, according to the NTSB.
Transportation Safety Board of Canada spokesman John Cottreau said investigators interviewed Proven today.
"As you know, he is injured and he has some recovering to do," Cottreau said.
Cottreau said that investigators are trying to gather as much perishable evidence in the field, such as scars in the trees and marks on the ground. Tuesday's thunderstorm complicated efforts. TSB-Canada took over the investigation because both both pilots are federal employees.
"[This data] can tell you for instance what angle the aircraft was coming toward the ground at, which might be useful in an analysis," Cottreau said. "We are doing a lot of this data gathering, but we aren't doing any analysis yet."
Investigators found the four corners of both aircraft—the noses, the tails and all four wings. The Beechcraft BE-35 was torn into two parts found about 1,000 yards apart, and one section did burn after the midair crash. Both aircraft were a mile apart after the midair crash, he said.
Radar data has been secured from air traffic control.
"It will show things like altitude, vector and direction," he said.
Three investigators from TSB-Canada were sent to Fauquier County on Tuesday.
"The No. 1 question is how long is it going to take. And what I can tell you is we are going to take the time that we need to ensure that we do a thorough job on this investigation to make sure that we answer what happened, why it happened and hopefully how we can keep it from happening again," he said.