Installing the airline plugin for VIM using Pathogen is pretty straight forward. You basically just need to add it to the bundle directory, and add a line to ~/.vimrc

First, go to the bundle directory.

cd ~/.vim/bundle  

Next, clone vim-airline from the github repository

git clone https://github.com/bling/vim-airline  

Then, add the following line to your ~/.vimrc file. This will allow the airline plugin to load up as soon as you start editing a file (without splitting first).

set laststatus=2  

Additionally, I had to add the following line to get colors working correctly.

set t_Co=256  

I also added the following line to hide the default mode (INSERT, NORMAL, etc)

set noshowmode