Performance limits for optimal microburst encounter

The performance limits of optimal aircraft control strategies for microburst encounter are presented. The purpose is to determine the “edges of the envelope” for no-accident aircraft penetration of microburst wind shear. Over 1,100 optimal trajectories have been computed for jet transport and general aviation aircraft flying through idealized microbursts. They have been generated using a Successive Quadratic Programs trajectory optimization algorithm, which directly handles inequality constraints. Qualitative aspects of the best strategies provide a composite picture of good control in a microburst. Variations of the optimal no-accident performance with microburst type, intensity, length scale, and location define performance limits. Optimal performance limits show three length-scale regimes. At short length scales, hazards usually associated with gustiness predominate. At intermediate length scales, a degraded ability to maintain flight path and/or vertical velocity sets the limiting microburst intensities for no-accident performance. At very long microburst length scales, the hazards associated with intense steady winds are the critical safety limits. The ability to successfully transit a microburst also varies strongly with microburst location. The performance limits show that both aircraft, if controlled properly, can penetrate some very severe microbursts. Nevertheless, even the best control strategies have their limits. The jet transport performance limits occur at higher microburst intensities than the general aviation limits.