You may be late
My general recommended timeline:
(Times back from when you want to get your first paycheck from an airline)
-Start networking, reading forums, paying attention to peers getting hired, considering a run at the airlines: start of last assignment or two, no less than 3-4 years out
Hit publish on the 50% solution app: > 1 year out.
-Have app polished and refined to the 90% solution: 1 year out.
-Start interview prep in earnest: 1 year out
-Feel fully prepared, app at 99%, suit ready, resume ready: 6-9 months out
-Start “practice” interviews, lock down backup jobs at airlines that aren’t #1 or 2 on your list, regionals: 6 months out