Deputies, along with the Utah Highway Patrol Aero Bureau, flew to the last-known GPS coordinates recorded by the plane's spot beacon where they found burning wreckage.
Officials believe the single-engine Cessna 182 crashed after taking off from a small backcountry air field, just outside the Dark Canyon Wilderness area. After liftoff, the plane flew east but crashed for unknown reasons about one mile from the airstrip.
Mark Francis, the owner of Red Tail Aviation and Newby's brother-in-law, said the Texas men arrived in their own plane which is registered to Kyle Richardson and hired Newby "to be their tour guide."
Francis said Newby has been flying since he was in his 20s and had been a flight instructor for years.
"He's a guy who lights up the room always joking and pulling pranks keeps us all on our toes," Francis said. "He was a big, shining part of this operation, and we'll miss him."
Newby is survived by his wife and two grown children.
Francis said of the Texas men: "Our hearts go out to their families."
Francis, who went to the crash site Thursday, said it was "very remote," requiring a drive of 30 miles on dirt roads, followed by a two-mile hike over rugged terrain that required "a lot of climbing."
He said he hadn't "any idea at all" how the crash occurred. He said investigators with the National Transportation Safety Board were expected to be at the scene on Friday.
UHP officials said they were called out to search for the plane about 10 p.m. Wednesday. They arrived in the area about 1 a.m. Thursday and located the plane about 3 a.m., according to a sheriff's office official.
The bodies of the victims were removed by a UHP helicopter about 4 a.m. Thursday and taken to the nearest highway, State Road 95. The remains were taken to the state medical examiner's office in Salt Lake City, according to the sheriff's office.
Neighbors in Midland told The Associated Press that Kyle Richardson is a petroleum engineer.
The Ozona Stockman reported that Kyle's parents, Wade and Jane Richardson, of Ozona, Texas, are Crockett County ranchers and the owners of several Dairy Queen restaurants in west Texas, including the one in Ozona, a town of about 3,000 residents.
The names of the victims have not been officially released, pending positive identification of their remains.
Stephen Hunt contributed to this report.