Report of the Second Piloted Aircraft Flight Control System - Acgsc.org

The configuration described above remlte in a control char-taistic
in which, effectively, wheel force commande rate of change of
attitude. If the integrator is removed, the lateral control ChBSacterirtic
becomer similar to that of an automobile, in which wheel
force comr~andr a rate of turn. Integrators for the B-17 inrtellation
were conrtructed and grand-cheeked but were never inrtalled. Improved
intagratore will be a feature of the C-54 installation.
In Figure 5, the pilot 1s controls are not oonnected mechically to
the control eurfece, and motionr of the control taurface induced by artificial
atability 8ignd.r from the rensing element are not aocoapded by
rimilar motionr of the cockpit controle. This mean8 that the pilot ir
not rubjected to the poesibly disconcerting phenomenon of having the
control wheel move about in a manner aich he does not command. Ae far
ar the pilot ir concerned, he ir flying an aircraft which ir more atable,
but just ar controllable ar the rame aircraft would be if it had a more
oonvsntional control eyrtcm.
The force wheel eyetcm of Figure 5 la a ro-callod #full-poweredn
ryrtear, in which none of the power necessary to more the control rurfacer
ir mupplied by the pilot. This ie in contrast to the systemr prdourly
described, which are boost eyetar, eince a emall portion of the power
neceerary to move the control surfaces is applied by the pilot through
the rigid mechanical connection between the cockpit controlr and the
control arrfacer.
In a full powered ryetem there is no conventional control #feeln
for the pilot, ro it ie derirable to include artificial feel in the form
of a bungee rprlng, and bobweight wlth proviaions for variation of the bungee
characterietior with airspeed. The effect of trim may be rimrrlated by including
mean. for varying the cockpit control position at which no force ir
qerisnced. It may be dedrable, however, to fix the rtick and fly with
forcer alone. Thir war to have been tried on the B-17. In thir case
there would be no control porition gradient and no dieplacement of the
rtick wlth varflng trim.
Another force wheel eyrtem using full-powared control e+rfaoee ir
ahom in Figwe 6. Thir arrangement ir rimilar to that jaet dercribed,
arcapt that the artificial feel bungee has bean replaced by a wheel position
Berm ryrtm. !Che force-displacement gradient be conveniently abjarted,
and, in fact, may be mede nonlinear if desired. Honlimar gredisntr are
mupporod to be psychologioally optimum. Proririons are &own for the introduction
of alrmpeed aad #gn force rignale into the force &eel preamplifier
to eimultaneaurly alter the control rurface and wheel force gradientr.
Thir is essentially the aystam which ir to be flown in the w.