The laborious process of manually entering cryptic latitude
and longitude data for each flight waypoint created high
crew workloads and frequently resulted in incorrect data
entry. The requirement of a separate control panel for each
long-range system consumed precious flight deck space and
increased the complexity of interfacing the systems with
display instruments, flight directors, and autopilots.

The concept employed a master computer interfaced with all
of the navigation sensors on the aircraft. A common control
display unit (CDU) interfaced with the master computer would
provide the pilot with a single control point for all navigation
systems, thereby reducing the number of required flight deck
panels. Management of the various individual sensors would
be transferred from the pilot to the new computer.

Since navigation sensors rarely agree exactly about position,
Naimer believed that blending all available sensor position
data through a highly sophisticated, mathematical filtering
system would produce a more accurate aircraft position. He
called the process output the "Best Computed Position." By
using all available sensors to keep track of position, the system
could readily provide area navigation capability. The master
computer, not the individual sensors, would be integrated into
the airplane, greatly reducing wiring complexity.

To solve the problems of manual waypoint entry; a pre-
loaded database of global navigation information would
be readily accessible by the pilot through the CDU. Using
such a system a pilot could quickly and accurately construct
a flight plan consisting of dozens of waypoints, avoiding
the tedious typing of data and the error potential of latitude/
longitude coordinates. Rather than simply navigating point-
to-point, the master system would be able to maneuver the
aircraft, permitting use of the system for terminal procedures
including departures, arrivals, and approaches. The system
would be able to automate any aspect of manual pilot
navigation of the aircraft, When the first system, called the
UNS-1, was released by Universal in 1982, it was called a
flight. management system (FMS). [Figure 3-44]

Figure 3-44. A Control Display Unit (CDU) Used to Control the
Flight Management System.