necessary for the control wheel to actually turn the rudder or operate the air-
plane’s wing surfaces. The large lever that controls the landing gear of an air-
plane no longer actually moves the gear up and down. No, the controls simply
send signals to electric or hydraulic motors that do the actual movement.
It would be entirely possible to take the huge room filled with controls for
the power plant or the large control panels of the ship and commercial airplane
and put them on a small computer: Show the displays on a couple of colorful
computer screens and operate the controls with a simple keyboard, a small
switch panel, and the ability to turn things on and off just by touching appro-
priate areas of the screen. Not only could one do this, but it has been done:
Excellent examples of these displays and controls exist in the research and de-
velopment laboratories for all these industries and, for that matter, in the game
world, where one can often purchase excellent simulations of the real devices
as games for the home computer—simulations that are good enough to be the
model for a real control.
The new technologies seemingly eliminate the need for the large controls re-
quired by the old-fashioned mechanical technology. The lesson has not been
lost on designers. The new airplanes from Airbus have no control wheels. In-
Figure 18.1
Cockpit of the Boeing 747-400 Airplane. This is a modern ‘‘glass’’ cockpit, with most of the me-
chanical gauges of older aircraft replaced by computer-controlled displays. The captain sits in the
left chair, the first officer in the right. The control wheels (just in front of each pilot’s chair) are
yoked—connected so that both move together. Most of the instruments and controls in front of each
pilot are duplicated for the other. Many of the instruments and controls in the center are shared.
(Photograph courtesy of Boeing Commercial Airplane Group.)
444 Donald A. Norman