The H∞ loop-shaping design procedure (referred to hereafter as LSDP) was used to design fixed gain controllers for the HIRM. It was found that a single fixed gain controller designed for the linearisation ini3005, performed adequately over the whole flight envelope of the HIRM. As scheduling would most probably be required for a real fighter aircraft with a much wider flight envelope, the control law has been developed with a structure suitable for scheduling. As the longitudinal and lateral dynamics are essentially decoupled, two separate controllers were designed. The lateral controller has an inner loop for stabilisation and an outer loop for tracking. The longitudinal controller has one single loop that provides both functions. A second fixed gain controller was designed for the HIRM using the multi-model approach described on pp. 67–72 in [247]. This method enables the designer to find a fixed gain controller that makes the normalised coprime factor cost function flat over the whole flight envelope. Details about how to apply this method can be found in [191]. The design team found it relatively easy, even with the limited time available, to satisfy the specifications set out in Chapter 27.