The airscent K9 is the type most frequently encountered. This K9 finds lost people by picking up traces of human scent that are drifting in the air and looks for the “cone” of scent where it is most concentrated. Most K9s do not scent discriminate and will find all living people in the area. The handler will instruct the K9 with a command to find others and they will move on to search more. These K9s are best used in wilderness situations where there is a low probability of encountering other people.
Some K9s will discriminate scents if they have been trained to do so. Giving them an article with the scent of the missing will enable them to locate that person even if other people are around. The success of an airscent K9 may be affected by a number of factors, including wind conditions, air temperature, time of day and terrain. The best conditions for airscent K9s to work are early mornings or late afternoons on cool, cloudy days when there is a light wind.