Zacks Transportation - Airline industry's prospects look bright on the back of a rosy air travel demand scenario. Declining fuel costs also bode well for airlines. This is because expenses on fuel represent a key input cost for airlines.As a result, we believe that investors interested in the industry would do well to bet on stocks like Ryanair Holdings (RYAAY) , Southwest Airlines (LUV) and Allegiant Travel (ALGT) for higher returns.About the Industry The Zacks Airline industry players are engaged in trans ...