Initial attack of patrolling plane

This is from the Wiki:

Another form of air combat can be triggered via the patrol command: In this mode the airplane automatically attacks all enemy units within its patrol radius, but units are not locked in combat in this mode. This means the patrol destination of a patroling airplane can also be re-positioned anytime.

• During patrols aircraft deal damage every 15min instead of the standard 30min. The damage values of both sides are reduced accordingly by 50%.
• If 2 enemy aircrafts patrol in the same area with overlapping patrol circles, they attack each other as well, while also returning defence damage to the other plane. In such a case the applied damage depends on the size of the area that is overlapping, with full damage only being applied if more than half of the circle areas overlap.

  QUESTION: At 0 (zero) minutes, that is, when an enemy unit (plane or otherwise) is withing the patrol area, is any damage inflicted? I understand that damage will occur at 15 minute intervals, but I clarification about that initial moment of contact.

  The reason I'm curious concerns the case of an enemy plane that flies in to strike a ground target within my friendly plane patrol area. Let's say the enemy flies in, strikes my ground unit, and then flies out of the patrol area, all within 10 minutes. Does my friendly patrolling plane inflict any damage on the intruder? I hope so.

  Thanks.