This paper examines the status and prospects for widespread application of Al-Li alloys in aircraft structures. Particular attention is paid to the damage tolerance engineering properties of fatigue crack growth and fracture. At present the application of Al-Li alloys is very limited. This is because they are not direct replacements for conventional alloys and the basic material costs are usually too high. Widespread application of Al-Li alloys may well require a new generation of alloys, especially for primary structures. This will take at least five years. In the meantime, experience will be gained by selective application of the current generation of Al-Li alloys in secondary structures.