Andy B
500+ Star Club
Sorry to unearth this old topic. Facing the same issue, and on my part I think it's a bit strange in terms of game-planning.
You need a part in order to upgrade your Heli Repair Centre to service Goldfinches, but it requires you flying to a destination only a Goldfinch can fly to. And if the heli breaks down, then what? We've no choice but to sell the unrepairable heli and repeat!