Northern Territory has Aeroplane Pilot on it's
skilled occupation list so you could convert to a CASA ATPL and get a letter of assessment from them, apply to the NT for state nomination for a visa and then apply for a 190 (permanent) or 489 (provisional) visa through the skillselect program. If you are subsequently granted a visa you can then apply for a job with an Australian carrier. All the information you need on the visa nomination process is available on the NT visa website and information on skillselect can be found on the DIBP site.