Conformal fuel tanks are auxiliary fuel storage cells that can be attached to the outside of an airplane and are shaped to retain as much of the airframe's aerodynamic properties as possible. This means (usually) making tradeoffs between capacity and shape. The F-15 Eagle can utilize a set of conformal fuel tanks called FASTpack which can extend its range by nearly 40% while (I believe) still allowing the aircraft to go supersonic.

Log in or register to write something here or to contact authors.