Fire Control (Breakaway)

Maximum range for tracking is 40,000 yards. At ranges beyond 40,000 yards, the return echo will be too weak to maintain lock on. If unlock occurs, the system is automatically returned to automatic search, and the cycle of manual track and acquisition must be repeated to regain target tracking. Fire Control (Breakaway) The final submode of fire control is known as breakaway. This mode occurs automatically if the target is tracked to a range that would endanger the attacking aircraft. During automatic track of a target that has a decreasing range (attacking aircraft is closing on the target), the range circle is removed at the time the range to the target gets to 3,500 yards. In its place, a large X is displayed, which indicates time to breakaway from the attack (fig. 3-14). Also at this time, the steering dot will move to a position on the scope to indicate the safe direction for the attacking aircraft to turn to execute a safe breakaway. In the illustration, minimum range has been reached and the breakaway X has appeared. The steering dot is presently positioned to the right and above center. Bomb Director Mode When the bomb director mode of operation is selected, information is displayed on the PPI indicator. In this mode, the antenna automatically goes to sector scan, scanning a 60-degree arc, 30 degrees to each side of dead ahead. Antenna elevation is manually controlled. The PPI scope has a Figure 3-14.-B-scan presentation breakaway indication. Figure 3-15.-PPI presentation in bomb director mode. depressed center, which appears as a wedge-shaped scan on the indicator face, as shown in figure 3-15. The antenna is positioned in elevation so it will scan the surface of the earth during a bomb attack. The B-scope will only display the artificial horizon in the bomb director mode. The target tracking range and azimuth strobes appear on the indicator; they are moved manually so the marks form a cross hair effect, and are centered over the target to be tracked. Tracking is maintained manually in the bomb director mode. The azimuth and range strobes are controllable from 0 to 80,000 yards, and, in azimuth, 25 degrees to either side of center. IFF SYSTEMS Learning Objective: Recognize components and operating principles of an IFF transponder set and an IFF interrogator set. There are two systems that make up the IFF system on an S-3 aircraft. These systems are the AN/APX-76A and the AN/APX-72. Both systems work in conjunction with the radar set for total and secure identification. TRANSPONDER SET AN/APX-72 The transponder set provides Identification Friend or Foe (IFF) radar replies when challenged by a valid IFF interrogator. The IFF transponder 3-15