Before you can use Kali Linux for wireless scanning, it is important to know which wireless chipset your wireless adapter is using, as only certain wireless chipsets are capable of being put into promiscuous or monitor mode. For a list of supported chipsets, check https://www.aircrack-ng.org/doku.php?id=compatibility_drivers.
In the event that your wireless adapter is not supported, there are many USB wireless adapters that can be added to an existing testing platform for minimal cost.
Once you have determined that you have a supported wireless chipset, you will need to put wlan0 into the monitor mode by doing the following:
root@kali:~/# ifconfig wlan0 downroot@kali:~/# iwconfig wlan0 mode monitorroot@kali:~/# ifconfig wlan0 ...