The Dog Stars (Vintage Contemporaries) / Heller, Peter

Hig somehow survived the flu pandemic that killed everyone he knows. Now his wife is gone, his friends are dead, and he lives in the hangar of a small abandoned airport with his dog, Jasper, and a mercurial, gun-toting misanthrope named Bangley.
 
But when a random transmission beams through the radio of his 1956 Cessna, the voice ignites a hope deep inside him that a better life exists outside their tightly controlled perimeter. Risking everything, he flies past his point of no return and follows its static-broken trail, only to find something that is both better and worse than anything he could ever hope for.