Sending SMS through iPad Air's iMessages How do I send text messages to non apple devices with my iPad Air with cellular? I have the iMessage worked out but can't figure out SMS.
SMS's can only be sent through an iPhone, as it requires a carrier's plan and a phone number associated to it, which iPad's lacks of.
As stated by Apple:

Which Apple products support Messages using SMS and MMS?
To use Messages with SMS and MMS, you need an iPhone.