Airmon-ng command not found

Install the aircrack package first, then you will be able to use the airmon-ng command.

Here's how

Open a terminal and type:

sudo apt-get install aircrack-ng

You may now use the command.

sudo airmong-ng start wlan0

get THIS package and open that with Software center to install . Then you're done .

Then try with sudo airmon-ng start wlan0 it will be fine . Just now i tested myself.

Just try sudo airmon-ng in a terminal. It should work for you as worked for me.