Trend vector horizon is used to forecast for how many seconds?

• A. 5 seconds
• B. 10 seconds
• C. 15 seconds
• D. 20 seconds

Answer: (B)

Trend vector horizon is the short-term forecast window shown on radar that projects where an aircraft will be in the near future if it maintains its current speed and heading. The standard horizon is about ten seconds, chosen because it gives controllers a practical lead time to anticipate the aircraft’s path and maintain separation, without relying on longer projections that become unreliable due to speed changes, wind, or turns. A shorter horizon provides less forward visibility, while a longer one would risk inaccuracy, so ten seconds sits at the right balance for immediate tracking and decision-making.