*5.2.1. Template algorithm*

Template algorithm creates two virtual lines in front of the aircraft in the airspace. These virtual lines form two sections; the upper one is decided based on the pitch up maneuvering of the airplane, whereas the lower part anticipated the set clearance. The terrains monitored as the radar scans the airspace in front of the aircraft. The return signals collected and processed for storing range and angle to the region. A pull up command generated when the terrain or other object crosses the template line. On the other hand, when the terrain clears the template line, a pulldown command generated. This full down command, bring the aircraft to original set clearance decided by the pilot [4]. This system implemented using analog processing prior to the advent of digital circuitry. **Figure 4a** shows the template algorithm.
