Q: Is a 60watt MagSafe Power Adapter compatabile for a MacAir?

To quote from below linked article from Apple:

"Power adapters for Intel-based Apple notebooks are available in 45W, 60W, and 85W varieties. Although you should always use the proper wattage adapter for your Apple notebook, you can use an adapter of a higher wattage without issue."

http://support.apple.com/kb/HT2346

Best.

Yes you can but, if your MBA uses the new MagSafe 2, you'll need the $10 MagSafe 1 to MagSafe 2 adapter.