Dallas, TX-based airline heavyweight Southwest Airlines Co. (LUV) ) has been benefiting from improvements in air travel demand, consistent shareholder-friendly initiatives, cost-cutting measures and fleet modernization techniques. The decline in oil prices bodes well for bottom-line growth of airline stocks, and it is no different for Southwest Airlines.The positive sentiment surrounding the stock is evident from the fact that the Zacks Consensus Estimate for LUV's earnings has been revised upward in the pa ...