Formation flying is a phenomenon observed very often in the natural world, e.g. birds flying in a flock. The past decade has given a lot of emphasis on the research for the control of autonomous Unmanned Aerial Vehicles (UAVs) of the fixed-wing kind, in an effort to emulate the behavior of natural flocks. Emulating this behavior requires the construction of path following and formation control laws with the capability of adapting to changing situations, in a similar way as natural flocks can do. This thesis is devoted to studying Adaptive Vector Field Guidance laws and Adaptive Formation laws for fixed-wing UAVs. Formation control relies on an adaptive hierarchical formation control method for uncertain heterogeneous nonlinear agents with Euler-Lagrange (EL) dynamics. It is shown that various formations (T-V-Y formations) can be established using this method, tested using a Matlab/Simulink environment. Additionally, a distinguishing feature of this thesis is the development of a 3D-Simulation platform to perform a hardware in the loop (HITL) simulations (i.e. using the control hardware on board of an actual UAV): a Raspberry Pi is used to run the formation control algorithm and to communicate with a Pixhawk Cube autopilot board which contains the low-level control algorithm. The autopilot board is then connected to a 3D Simulator (Gazebo) and Ground Control System (QGroundControl). The proposed HITL platform promises to facilitate the testing and validation of guidance and formation laws in a much more realistic way than a Matlab/Simulink environment can do.