This document discusses Porter's five forces model and its application to the airline industry. It analyzes the competitive forces of industry rivalry, threat of substitution, threat of new entry, bargaining power of customers and suppliers in the aviation industry. It also discusses Porter's generic strategies of cost leadership, differentiation and focus and how airlines have implemented these strategies. Common mistakes in airline marketing strategies are outlined such as unclear objectives, improper diversification, overexpansion and overoptimism. Alliance strategies between airlines are also covered.