Average ASW patrol area for helo

[frpandore@free.fr]

Hi,

To fine tune my search pattern and to give my side the maximum chances to find hidden sub, i would like to know the average area covered by a standard ASW helo.

You surely have better chance to find a sub in a 50 square kilometers area than in a 100 square kilometers one.

For example, if you have to patrol a 100 square kilometers area, how many helos must be on station at the same time to be the most effective.

Or,

If you have just 1 helo, what is the best size of the patrol area ?

My English is not sufficient to find such an answer on the web. i find nothing in french.