In this lecture Dr. Ir. M. Voskuijl begins with recapping the material covered in the previous lecture. The first subject of this lecture is the performance diagram, which described the space of velocities and altitudes an aircraft can fly in. Next an analytical solution is derived for optimal climb, first tailored for low speed aircraft, and later to high speed aircraft. First however the matter of energy height is explained, which uses the kinetic and potential energy of the aircraft to describe the problem. This is then used to solve the case for high speed aircraft.