It's very hard to add weight to an aircraft, it has to be within the center of gravity to fly. To much weight forward or aft and the flight controls can't compensate for it.

Edit to add link

https://www.flight-study.com/2021/04/balance-stability-and-center-of-gravity.html

It's very hard to add weight to an aircraft, it has to be within the center of gravity to fly. To much weight forward or aft and the flight controls can't compensate for it.