The ornamental design for an americanflagducttape, as shown and described.
FIG. 1 is a top plan view thereof;
FIG. 2 is a bottom plan view thereof;
FIG. 3 is an end view thereof; and,
FIG. 4 is a right side elevational view thereof.
The tape is cut off at either end in FIGS. 1, 2, and 4 to indicate that no particular length is claimed. The broken lines shown in the drawings are for information purposes only and form no part of the claimed design.