When Martin needs to pay back Dr. F , all he needs you to do is buy a lot of heliport markers for 5,000 and buy one for every place except for the zoo. Once you bought every one you need, Martin will say that he's finally paid back his bill. Then you need to help people and play games until you get your first heliport plans. Give them to the builder and you need to get essences to make one. You can only place a heliport if you bought a heliport marker. Every heliport you make has to have a heliport maker to go with it. Then you can fly as long as you have a heliport where you want to fly. Yay!