Grateful to receive an offer, but still have a dilemma.

Hi everyone!!! So here is my dilemma. Your comments/feedback are much appreciated.

So, it's been about three months since I received a contingent offer for an airline job. I passed all of the prerequisites (background check, drug test, fingerprint). Now, I'm awaiting my formal offer letter, and training schedule. This could happen next week, next month, or maybe two months from now (I sure hope sooner),

Earlier today, I received an offer for a part-time job (25 hrs/week with possibility for overtime); no benefits, 401K, etc., since part-time; but still opportunities to apply for full-time positions. There would be a two-week training program; obviously, a significant investment of time and money.

What I'm asking, is would it be wrong to accept this offer, knowing in the back of my head, that as soon as the airline calls, I would leave? I'm pretty sure I already know the answer, but I'm always open to others' viewpoints.

Thanks in advance.