Assuming you didn't remove the USB installer before it was completed, it may have been a compatibility issue.
Here's the official documentation for installing Ubuntu on a Macbook Air.
(original thread above)
In case you'd like to attempt again, here's the documentation Macbook-Air specific, pulled directly from their website. Don't worry, I'm a copy and paste master [but I know what's going on, so copy and paste isn't a huge issue].
This is for recreating the installer USB stick, and specific instructions.
Prepare USB-Stick
1. In OSX
2. Download iso image to ~/Downloads
3. Open Terminal (a detailed description can be found here.
cd ~/Downloads
# convert iso
hdiutil convert -format UDRW -o ubuntu-14.04-desktop-amd64.img ubuntu-14.04-desktop-amd64.iso
open /Applications/Utilities/Disk\ Utility.app
# format the USB stick with MS-DOS VFAT
diskutil list
# check which /dev/diskX contains the USB stick - here it is "disk1"
# then unmount the usb-stick
diskutil unmountDisk /dev/disk1
# write img to usb stick - /!\ BE CAREFUL THAT disk1 REALLY IS YOUR USB-STICK
sudo dd if=ubuntu-14.04-desktop-amd64.img.dmg of=/dev/rdisk1 bs=1m
Install Ubuntu
- Restart and press "Alt"-Key on startup.
Make sure that the USB-Ethernet Adapter is inserted. (With a network connection the bcmwl-kernel-source module gets downloaded during the installation process.
Select first USB-device labled "EFI-Boot" and press "Enter".
No splash screen shall be displayed but the Ubuntu installation menu. See Identifying if the computer boots the Ubuntu DVD in EFI mode.
Select "Install Ubuntu"
Note: If booting into BIOS-Mode is a bad choice as you can currently only run on one core. Bug
Choose "Something else" for partitioning.
Please check the sizes in the list according to the partitioning for the step above.
OSX Disk Utility leaves unallocated partitions inbetween which usually are arround 128MB in size.
Do not try to delete these "blank" partitions.
2nd partition should be ext4 formatted and mounted "/".
3rd partition should be ext3 formatted and mounted "/home". (I use ext3 in order to use fuse-ext2 from OSX; ext4 is yet not supported)
4th partition should be swap (no format and mountpoint required)
Proceed...
The installation process should run through smoothly.
Restart with pressed "Alt"-Key.
Unfortunately selecting the "Windows" labled Partition (HD-icon) only displayed a black screen with a blinking cursor.
Reboot into OSX again and install "refind".
Download (Binary Zip-File) (Direct Download refind-bin-0.8.2.zip)
Open a Terminal
cd Downloads
unzip refind-bin-0.8.2.zip
cd refind-bin-0.8.2
sudo ./install.sh
Restart again. Now a Ubuntu labled "/efi/ubuntu/grubx64.efi" should be shown.
Select this an start it, now the grub-menu should be displayed.
Select "Ubuntu".
Now Ubuntu should boot.