The ornamental design for an aircraft fairing, as shown and described.
FIG. 1 is a front perspective view of the aircraft fairing showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a back view thereof;
FIG. 4 is a first side view thereof;
FIG. 5 is a second side view thereof; and,
FIG. 6 is a bottom view thereof.
The even length broken lines illustrate structure and environment that form no part of the claimed design. The single long dash and single short dash broken lines illustrate boundaries of the claimed design that form no part thereof.