How far out in advance would you suggest to start ECCC or another interview prep?

I've got 3 yrs until retirement and am starting the adventure now of seeking an airline position…

It's my understanding that once I'm within exactly 12 months from my official retirement date, I can technically start the interviewing process but just mention that I won't be available for work/class until 02 Jan 17 (for example), the date after my official retirement date?

So this gives me 2 yrs to prep?