Officials say no one was in the tower at Anchorage's Merrill Field airport early Tuesday morning when a small Civil Air Patrol plane took off from one of its runways, deepening the mystery of pilot Doug Demarest's flight that ended when he crashed into two downtown Anchorage office buildings.
Airport manager Paul Bowers said the tower's operating hours are 7 a.m. to 10 p.m. daily in the winter, and until midnight in the summer. The crash happened around 6:18 a.m., according to National Transportation Safety Board Region Chief Clint Johnson.
"This aircraft departed, obviously, prior to the tower opening," Bowers said. For that reason, he said he didn't know the plane's departure time, or if that could even be determined.
The FBI, which has taken the lead on the investigation, was tight-lipped Wednesday on the timing and other details of the crash. An FBI spokeswoman, Staci Feger-Pellessier, sent out a short statement Wednesday morning saying that the FBI generally does not comment on active investigations and would only say the FBI doesn't believe the crash was an act of terrorism.
She said the FBI "(does) not anticipate having any updates for at least two weeks."
Demarest was a first lieutenant in the Civil Air Patrol, a largely honorary ranking. He was also a licensed pilot and a photographer. His wife is an attorney who works on the sixth floor of the building first struck by the plane.
During a routine morning check of hangars at Merrill Field between 6 a.m. and 7 a.m. on Tuesday, crews found a hangar operated by the CAP's Polaris Composite Squadron with its main door open. There was no sign of forced entry, but the situation was unusual, Bowers said.
Bowers said he wasn't aware of any Merrill Field personnel who saw the plane take off, because the control tower was not yet open.
He said typical protocol is for pilots to self-announce from their radio on what's called the common traffic advisory frequency. Self-announcing is voluntary and would typically involve pilots stating their intentions -- the airport, the runway from which they're departing and their destination.
There's no requirement for such an announcement to be recorded on a frequency monitored by the Federal Aviation Administration, Bowers said. He said the Merrill Field airport did not record it if indeed Demarest made any announcement.
"During off hours … normally, there's not enough traffic to justify keeping the tower staffed," Bowers said. "Nobody's flying between 1 a.m. and 4 a.m., normally … an individual who does happen to fly during that time would be an anomaly."
There are two sets of rules for flying an aircraft: one set for flying by visual rules and the other for flying by instruments. Officials haven't said which set of rules Demarest was using. Radar can pick up aircraft flying under visual flight rules if the plane is high enough, but they are not routinely tracked by radar operators like an instrument flight.
Radar detection heights vary, and FAA spokesman Allen Kenitzer said he didn't know what it would be for downtown Anchorage. A spokeswoman at nearby Joint Base Elmendorf-Richardson did not return a call seeking comment about the airspace.
The CAP plane was not tracked by conventional flight tracking services. According to FlightAware.com, the plane's last recorded flight was in April 2013 in Southern California.
Civil Air Patrol officials have said Demarest's flight was "unsanctioned," but have not said whether the plane was stolen.
Correction: An earlier version of this story incorrectly reported the time of the crash. The plane crashed around 6:18 a.m., not 6:48.