The other plane, a DHC-2 Beaver owned by Mountain Air Service, was carrying four passengers and one pilot, Ms. Homendy said.
She said it was flying west-southwest toward Ketchikan at 106 knots, or roughly 125 miles per hour, at an altitude of roughly 3,300 feet. The collision happened at an altitude of between 3,200 and 3,300 feet, she said.
The bodies of two passengers and the pilot, all Americans, were recovered overnight. The Ketchikan Fire Department identified the pilot on Tuesday night as Randy Sullivan.
A fourth body was recovered Monday night, and two more bodies were recovered on Tuesday.
Ms. Homendy said she expected investigators to spend between five and seven days at the crash site.
“We will not be determining the probable cause of the accident in that time frame nor will we speculate on the cause,” she said. “We will however provide information that we are able to provide that is factual in nature.”
Neither plane was equipped with cockpit voice recorders or devices to record flight data, nor were they required to be, Ms. Homendy said. Aaron Sauer, the N.T.S.B. investigator in charge, said the planes were “not in a controlled area” at the time of the crash, which meant their pilots were not required to be talking to an air traffic control tower.
Ms. Homendy said investigators would examine how the pilots were trained, any medical issues they may have had and log books they kept.