Horizontal Control Effector Sizing for Supersonic Transport Aircraft

Abstract

The use of an automatic flight augmentation system is commonplace on a modern aircraft. Its benefits include alleviation of undesirable flight characteristics, reduction of pilot workload, and increase in performance and fuel efficiency. Therefore, feedback (dynamic) considerations should be included in determining the sizes of aircraft control surfaces. Traditionally, only static con- straints have been used for control surface sizing. For example, in the case of a horizontal tail of a given volume, constraints are cal- culated that limit the fore and aft travel of the c.g. Constraints that limit the forward c.g. position include 1) sufficient nose-up pitch acceleration at the rotation speed (nose-wheel lift off) and 2) suf - cient nose-up pitch acceleration at the approach speed in the landing con guration (go-around). Constraints that limit aft c.g. position include 1) at brake release with maximum thrust suf cient weight on the nose gear (tip back), 2) pitch-up acceleration at the rota- tion speed (nose-wheel lift off), and 3) suf cient nose-down pitch accelerationatminimum yingspeeds.1 However,fortheaftc.g. locations at the approach ight condition of a supersonic transport aircraft, dynamic constraints may be more restrictive than the static ones.