Continuous descent approaches for maximum predictability

The current paper presents an innovative vertical guidance law suited to fly R-NAV Continuous Descent Approaches (CDAs) with ground speed histories that are very stable to wind uncertainties. The guidance law ensures arrival times and ground velocity histories that are far more predictable than when flown with other vertical guidance laws. This, together with the use of ground automation, could potentially help introduce CDAs in high density traffic airspaces and thus benefit from their huge environmental and economical advantages. The mentioned guidance law was derived using linear aircraft dynamics theory, and the results were validated through simulations using a point-mass aircraft model based on Boeing performance data. The simulations also reveal that the proposed law does not compromise noise impact, fuel consumption or flight time with respect to other idle descents based on existing vertical guidance laws.