User Guide

Appendices
264
Appendices
265
AlliedSignal KLN-89 GPS
GPS—WAVE OF THE FUTURE
One of the most remarkable developments in avionics dur-
ing the past decade has been that of the Global Positioning
System (GPS). In that short time, it’s gone from an exotic system
that only the military could use (or afford) to a general utility that’s
become indispensable to many user communities.
Nowhere has this been more evident than in aviation. For
the first time, there was a highly-accurate and dependable navi-
gation sensor that could work in even the smallest aircraft, and
would do so worldwide and in any weather. The first unit gener-
ally available for lightplane use, which wasn’t even a dedicated
aviation system, was Trimble’s “TrimPack.” At about the size and
weight of a (hardcover) Tom Clancy novel, and able to store only
a relative handful of waypoints, each of which had to be labori-
ously “scrolled in” by the pilot, the TrimPacks nonetheless went
out the door as fast as Trimble could build them, despite a $5000
price tag. Today, you can buy a unit that outperforms the old
TrimPack by far, including having every airport and VOR in the
entire world pre-stored in its database, for less than a tenth as
much...and it’ll fit in your shirt pocket!
KLN-89
In this chapter, we’re going to concentrate on one particular
GPS, the AlliedSignal KLN-89. Why? Because this is the unit
installed in three of the airplanes in this release of FLY!: the Cessna
172R, the Piper Malibu Mirage, and the Piper Navajo Chieftain.
This also illustrates one of GPS’s strong points: a single unit, small,
light, and cheap enough to be appropriate for even a fixed-gear
single like the 172R, has enough capabilities and functions to
meet the needs of a pressurized single or a commuter twin.
(Indeed, you’ll find quite a few of them in the panels of corporate
turboprops and jets, too.)
Appendices