NORTH SALEM, N.Y. — Officials expect little progress Monday in the search for a downed plane, which is believed to be carrying the longtime owners of a Danbury restaurant. Rescue teams on Sunday found the back portion of the tail’s fuselage and what appears to be the passenger compartment in a Westchester County reservoir, but those pieces were too heavy to be pulled, said Adam Bosch, a spokesman for the New York City Department of Environmental Protection.