From the Alaska Dispatch News:
Troopers, the Anchorage Fire Department, the Alaska Air National Guard, the U.S. Coast Guard and the Civil Air Patrol are looking for the pilot and any passengers from a small plane that was found on the mud flats of Knik Arm early Friday after an all-night search.
Troopers said the plane was discovered at 6:10 a.m. Friday about 2 miles northeast of the Birchwood Airport, but that no people were found in the area. The plane was upside down and partly submerged and appeared intact but may have been moved by the tide from where it went down, according to Alaska Air National Guard spokesperson Lt. Col. Candis Olmstead.
Troopers believe the plane may have been flown from the McGrath area but said they had no reports of overdue aircraft.
The Guard's Rescue Coordination Center said it got report of a plane crash just after midnight. An Air Force C-17 Globemaster aircraft was flying a training mission near the crash area and was diverted to assist in the search because it was outfitted with night-vision equipment.
After the searchers were joined by Civil Air Patrol aircraft and helicopters from the 210th and 211th Rescue Squadrons, the plane was found, said Olmstead.
Coast Guard and fire department water rescue boats were also sent to the area to look for the plane's occupants but had to withdraw because of the outgoing tide. They were planning to return in late morning, Olmstead said.
Troopers are asking anyone with information on the plane or its occupant(s) to call them at 907-352-5401.