Which statement correctly describes a PPI?

• A. Shows only a sector in front
• B. Center on the aircraft with a 360-degree top down view
• C. Cannot display alpha scans
• D. Is displayed only on military aircraft

Answer: (B)

A Plan Position Indicator (PPI) is a radar display that gives a plan, or top-down, view of everything around you. The own-ship symbol sits at the center, and radar returns appear around in all directions, with bearing around the circle and distance indicated by how far from the center the return is. This 360-degree perspective lets you see where traffic or objects are relative to your aircraft, not just what's in front.

That’s why the statement describing the PPI as centered on the aircraft with a 360-degree top-down view is the best choice. It captures the key feature of a PPI: a circular, all-around picture with the aircraft at the center, helpful for situational awareness in any direction.

The other options don’t fit because a PPI is not limited to a forward sector, it can display radar returns around the full 360 degrees; it can show different types of radar data (not solely “alpha scans”); and PPIs are used on both civilian and military aircraft, not only military ones.