The Wind Merchant - The Wind Merchant, #1

The skies are full of floating cities, sky pirates, and airships collecting secrets on the wind. But whatever you do, don't fly beneath the clouds. Out of the ashes of The Clockwork War, mankind rose above the clouds to begin anew with the Atmo Project, a group of twenty-one flying cities running off the overabundant resource that destroyed the world below. Nearly a century later, one-third of the cities have fallen from disrepair or sky pirate attacks.
When fledgling wind merchant Ras Veir inadvertently disrupts the natural fuel source keeping his home city of Verdant aloft, he must fly his airship clear across Atmo to right his wrong. But he can't do it alone, and adventure-minded girl next door Calista Tourbillon wouldn't dream to pass up an opportunity to escape Verdant with her childhood friend, especially if it means tangling with dread sky pirates, clockwork automatons, and the remnants of the long-forgotten world beneath the clouds to retrieve a rare element on the wind from a place known only as The Wild.