The purpose of this report is to present a broad outlook on eligible candidates for technology trends which will drive the development of combat air platforms with an approximate operational introduction date of 2040. The analysis is categorised by subsystems such as propulsion, weapons and sensors. For each subsystem, technology trends which may increase its performance substantially are summarised. In addition, a short roundup of ongoing international combat aircraft development projects is presented, with the most central and visible technology trends and focus areas highlighted. Quantum leaps in technology are necessary but not sufficient prerequisites for radical changes in the air combat environment; they must be combined with, or preferably be preceded by, thorough concept development. Finally, several new (and re-emergent) combat aircraft concepts are briefly presented, which could gain in relevance depending on quantum leaps in different technology areas. The basic idea is that if technology areas evolve incrementally, the trend towards bigger and more expensive multirole platforms will probably continue; for this trend to be reversed by new combat aircraft concepts, quantum leaps are required within one or more of several technology areas.