Look, given the political mess you have, for all you know bangladesh's finances will be way worse off in that time period.
Bangladesh currently is having massive power cuts and rolling failures in gas and coal fired power plants. Russian nuclear plant progress is delayed at the very least and bangladesh has to pay interest on the loans. Then there is Indian power bill due. Not to mention, it seems the current government is busy reviewing and possibly renegotiating almost all of these deal. Plus Bangladesh will need more forex just to keep itself fed and imports going.
I believe at some point of time in coming months or may be year or so China will jump in and will provide much needed liquidity and will snatch a large number of infra projects, at its terms. It will be playout of Sri Lanka once more. Bangladesh will get infra but not the means to payback the infra and other loans and will have to concede some advantages to China and may be some land or Island for ports. And BD will be in debt trap cycle.
So yeah, forget about it. BD is not going to have enough money to buy fifth gen planes.