In Grand Theft Auto (GTA), drop tanks are external fuel tanks that can be attached to certain aircraft in the game. They are purely cosmetic and do not have any functional use in the game. In aviation, a drop tank is an auxiliary fuel tank that is externally carried by an aircraft. It is expendable and often capable of being jettisoned. The primary disadvantage with drop tanks is that they impose a drag penalty on the aircraft. External fuel tanks will also increase the moment of inertia, thereby reducing roll rates for air maneuvers. Some of the drop tanks fuel is used to overcome the added drag and weight of the tank. Drag in this sense varies with the square of the aircrafts speed. The use of drop tanks also reduces the number of external hardpoints available for weapons, reduces the weapon-carrying capacity, and increases the aircrafts radar signature.