ADP 3-90, page 74

Chapter 4 4-14 ADP 3-90 31 July 2019 4-81. Units conduct defensive operations and designate FPFs for each of their supporting artillery units and mortar platoons. Both direct and indirect-fire weapons can provide FPFs. A direct fire weapon system’s final protective line is a form of FPFs. Commanders can only assign each weapon, firing battery, or platoon a single FPF. An FPF is a priority target for that weapon or unit, and those weapons or units are laid on that target when they are not engaged in other fire missions. When an enemy force initiates its final assault into a defensive position, a defending unit initiates its FPFs. Air and Missile Defense 4-82. Army air defense artillery forces operate interdependently with other elements of a joint and multinational team by providing air and missile defense. They contribute to the deterrence or defeat of enemy aerial threats by protecting the force, protecting high-value assets, and enabling a force’s freedom to operate. This mission is normally accomplished within a joint theater-wide structure and requires integration and close coordination between Army air defense artillery forces and other counterair forces. 4-83. Freedom of movement is essential to a successful defense. During large-scale combat operations, most friendly forces will not initially operate under the protection of air superiority. The joint force commander normally seeks to gain and maintain air superiority as quickly as possible to allow all friendly forces, not just ground forces, to operate without prohibitive interference from enemy air and missile threats. This counterair mission integrates both offensive operations and defensive operations by all joint force components. In an environment where air and missile threats exist, a defending ground force operates within a joint counterair operation designed to attain the degree of air superiority required by the joint force commander to accomplish the mission. 4-84. Ground commanders mitigate the risk of air and missile attack through various activities. These activities include camouflage, concealment, military deception, dispersion, redundancy, and protective construction. These activities improve unit survivability by reducing the likelihood of being detected and targeted from the air and by mitigating the potential effects of air surveillance and attack. Units improve survivability by detecting air and missile launches, predicting impact points, providing threat identification, and disseminating early warning. SUSTAINMENT 4-85. Commanders address several unique sustainment considerations in the defensive plan. Priorities for replenishment normally include ammunition and materiel to construct obstacles and defensive positions. There is usually a reduced need for bulk fuel. Some situations may have an increased demand for decontaminants and CBRN collective and personal protective equipment. Commanders consider stockpiling or caching ammunition and limited amounts of petroleum products in centrally located positions within the MBA. Commanders plan to destroy those stocks if necessary as part of denial operations. The supply of obstacle materials in a defense can be a significant problem that requires detailed coordination and long lead times. Commanders consider the transportation and manpower required in obtaining, moving, and uncrating barrier material and obstacle creating munitions. 4-86. Sustainment unit commanders and sustainment staff officers understand their supported commander’s intent. They establish support priorities in accordance with that intent and plan sustainment operations to ensure support for the overall operation. Commanders also address sustainment during branches and sequels to a defensive plan, such as a counterattack into the flank of an adjacent unit. This allows sustainment units to anticipate the needs of the maneuver units they support. 4-87. Maneuver units resupply regularly in case an enemy breakthrough disrupts sustainment. The sustainment enterprise may deliver combat-configured loads to its maneuver units. Combat-configured loads are typically packages of potable and non-potable water, CBRN defense supplies, barrier materials, ammunition, petroleum, oil, and lubricants (collectively known as POL), medical supplies, and repair parts tailored to a specific size unit. Sustainment organizations resupply their supported maneuver units until those maneuver forces request otherwise. Commanders use information systems to accurately tailor these combat-configured loads to the demands of supported maneuver units.