In Sky Force 2014, at the beginning of the game the player has 10 spaceships available:
How to increase this number?
E.g. I have 12 now, and didn't notice when it increased:
When you play any mission and find a "CARD" in a crate on the ground, and beat the level. You are awarded to keep the card. The cards consist of perks that help you in the game. 3 of the cards adds 1 extra Plane in your hanger. I've found 3 cards each, so i have 19/19 planes in my hanger. Hope that Helps.