Another unmanned drone aircraft will take to the skies over Arizona's border with Mexico.

FOX News Radio's Jeff Monosso reports as part of our ongoing series on national security:

Securing America:

A new Predator B becomes the fourth unmanned aircraft in Arizona's fleet to Patrol the U.S.-Mexican Border searching the ground and collecting evidence without being detected.  In all, six drones patrol the border from California to Texas costing tens of millions of dollars, which critics question along with safety issues.  But since the program began six years ago the Predator B's have helped capture thousands of illegals and tens of thousands of pounds of drugs.

Jeff Monosso, FOX News Radio.