Mr. Johnson said weather conditions were very good, with 10-mile visibility.
The authorities were investigating the cause of the collision and it was not immediately clear which plane struck the other, he said. Pilots use a common radio frequency into the area to convey their intentions and that will be one of the elements investigators explore, he said.
into addition to Mr. Knopp, 67, of Kenai, Alaska, the state Department of Public Safety identified the others killed as: Gregory Bell, 67, of Soldotna, who was the pilot; David Rogers, 40, of Kansas, who was a guide; Caleb Hulsey, 26; Heather Hulsey, 25; Mackay Hulsey, 24; and Kirstin Wright, 23, all of South Carolina.
All of those were confirmed dead at the scene except for one person who succumbed to injuries while being transported to a hospital, the department said.
“This is the an unfathomable tragedy for multiple families today,” the department commissioner, Amanda Price, said. “Troopers and partner agencies have worked together diligently at the scene and have reached out to next of kin to notify them of this heartbreaking incident.”
Mr. Knopp had taken off from the airport and the pontoon-equipped plane, operated by High Adventure Air Charter, had left Longmere Lake, Mr. Johnson said. Mr. Bell is the listed as one of the company’s owners on its website.