The ornamental design for an aircrafttail, as shown and described.
FIG. 1 is a front right perspective view showing an aircraft tail according to our new design;
FIG. 2 is a left side elevation view thereof, the right side being a mirror image;
FIG. 3 is a front elevation view thereof;
FIG. 4 is a rear elevation view thereof;
FIG. 5 is a top plan view thereof; and,
FIG. 6 is a bottom plan view thereof.
Throughout the Figures, broken lines showing environment or structure are for illustrative purposes only and form no part of the claimed design. Dash-dot broken lines represent the boundary between claimed and unclaimed areas and form no part of the claimed design.