Hi,
yes it is
Used planes can only be bought cash. But you can go to the bank and ask for a loan. That loan will not be tied to the plane you buy, so you don’t get a reduction on the interest rate.
And as Firtree pointed out, once you own one plane the bank will give you higher loans in the future. The more assets you have, the more the bank will trust you.
By the way… if you go to the bank, you can choose the amount of money you want to borrow through a drop down menu. If your airline is fairly new, the maximum may be something like 200.000 dollar. It is however possible that your limit is 400.000 dollar or more. To find out your actual limit, keep borrowing money until the bank says "no more". If you pay the money back within minutes, your interest will be nothing or almost nothing.
Jan