ive been looking around for solutions but neither 'nomodeset'-option nor i915.modeset=0 helped me. I have a Macbook Air Mid 2011 (with Intel Graphics 3000). Im trying to boot it from my USB Stick - which works fine on my Desktop PC (not a Mac) - but when I try booting then, I only get a black screen and after a few seconds the indicator light on my USB stick is completely silent. Nothing else happens. I’m using I’m currently using Ubuntu 15.04 64-Bit.
I don't think that your older Macbook Air is supported although it does have an Intel CPU so you might be able to get the 32-bit version to work.