The problem of communication delays in the information exchange between aircraft is the focus of the present chapter. First, a delay-dependent formation control scheme is developed in the full state information case in the presence of time-varying communication delays and under a fixed and undirected communication graph. The extension of this result to the case of a directed communication graph containing a spanning tree is discussed next in the presence of arbitrary constant communication delays. Then, under the same assumptions on the communication delays, formation control schemes are designed without linear-velocity measurements. In particular, the virtual vehicles approach is used to design delay-dependent (delay-independent) formation control schemes under an undirected (directed) communication topology.