In the late 1980s, some 150 Warthogs were modified to OA-10A standard in order to replace the OA-37A Dragonfly and the OV-10 Bronco in the forward air control (FAC) mission. Only a minimal conversion was undertaken, limited mainly to installation of VHF and UHF radios to permit direct communications between the OA-10A and ground units. No attempt was made to fit any sort of night sensor or laser designator system—or even a high-frequency shortwave radio—which places serious limits on the effectiveness of the Warthog in the FAC role.
The job of the forward air controller is to spot, identify, and mark targets for close air support aircraft. In Vietnam, this mission was generally undertaken by the Cessna O-2 Skymaster, a militarized light civil aircraft, and the OV-10 Bronco. These had little chance of survival over North Vietnam, so the “Fast FAC” was conceived: a 2-seat jet fighter (usually an F-100F Super Sabre) equipped with smoke rockets and sometimes a hand-held laser designator known as Pave Nail. “Nail” has remained a standard FAC call sign ever since. In the 1970s, these were replaced by conversions of the A-37B Dragonfly (itself a modified Cessna T-37 "Tweet" jet trainer), but by the 1980s these were themselves not considered survivable against the modern air defense threat, so the USAF turned to the rugged A-10A.
The easiest way to locate enemy ground forces is to fly in their vicinity and draw their fire. Thus OA-10s fly in pairs, with one acting as bait while the other watches for enemy fire, as was done in some of "armed reconaissance" patrols during Desert Storm. Armament is generally limited to 7- and 19-round rocket pods armed with 2.75” marker rockets. These have white phosphorus (WP) warheads that form a thick white cloud when detonated (they are also very effective incendiary devices in their own right). The A-10’s maneuverability enables it to roll in quickly against any target that reveals itself, and then evade return fire at low altitude. Even with the A-10’s survivability features, this is a very dangerous mission that would only be used when most of the enemy’s air defenses have already been beaten down, or in a dire emergency (an enemy breakthrough, or friendly units being overrun).
The lack of a laser designator is a serious handicap, because OA-10s cannot illuminate targets for other A-10s (or for Marine Corp F/A-18s with AGM-65Es). Given current budget constraints and the US Air Force's committment to more exotic aircraft, it is a fundamental weakness that doubtfully will ever be rectified.
