Credit Ratings

What is the practical purpose for the credit ratings? Currently my airline’s rating is at AA because it just started a new week and the leasing costs came in, while in the previous week it was at AAA. Is it a reputation status of sorts to other players or not?

It will affect the amount of loans you can take and the interest you may pay on these. The lower the rating, the lower the amount you can loan and the higher the interest.