Longitudinal aerodynamic characteristics—part 2
CHAPTER 7
7.1 BOB WEIGHTS AND SPRINGS
The control-force characteristics of manual-control systems can be modified by the introduction of weights and springs, as illustrated schematically in Fig. 7.1. When a spring, or bungee, is used as in Fig. 7.16, it is
Control column-
nW
(a)
Fig. 7.1 Bob weight and spring, (a) Bob weight. (6) Spring.
usually so designed that it exerts a nearly constant force on the control column. Thus both weight and spring require an additive stick force ДP to maintain equilibrium. These forces are
ДР = nW – Ъ
ДР — Tb
where n = 1 for rectilinear flight, and is given by (6.10,4) for a pull-up.