User Guide

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GLOBAL POSITIONING SYSTEM (GPS)

It’s really a sign of the times that even the most basic air-

plane in FLY! - the “lowly” Cessna 172R - now comes with a GPS

as standard equipment. Only a few years ago, GPS was consid-

ered a highly exotic (and extremely expensive) system for world-

wide navigation, suitable only for the heaviest bizjets. Now that

you can buy a basic handheld version at Wally World for a cou-

ple of hundred bucks, it’s also become the de facto navigation

standard for new light aircraft.

There are some very neat things about GPS: since it’s based

on satellites, rather than ground stations, it works anywhere in the

world. And since it’s digital, its remarkable accuracy - within 300

feet at worst, and generally much better - remains the same any-

where you use it. In normal mode, one dot of deviation (either on

the GPS’s own display or on a CDI connected to it) represents one

mile off course, whether you’re a thousand miles from the way-

point or right on top of it.

FLY’s airplanes use the Bendix-King KLN-89 GPS. With the

exception of the 89B extensions, almost all of the system’s features

are implemented in FLY! The displays you’ll find yourself using

most often (and which are implemented here) are the four “NAV”

pages. The first gives you the name of the waypoint you’re flying

to, an electronic CDI, numeric displays of both the desired track

or DTK - the course you should be flying to get to the waypoint -

and the actual track, the course over ground that you actually are

flying at any given time, groundspeed, and time remaining until

you get to the waypoint.

The Bendix-King ADF used in FLY! has standby and active

frequencies that work exactly the same way as for the nav and

comm radios. It also has a stopwatch that works the same way as

the ones in the KX-155s, so now you have three timers at your dis-

posal - say, one to show how soon you’ll reach the next check-

point, one to show when to switch fuel tanks, and one to remind

you when to open your brown bag flight lunch. In fact, you real-

ly have four, since the ADF also has a flight timer that starts when

you turn on the radio power (in fixed-gear airplanes) or when you

lift off and retract the gear in folding-roller ones. The FLT/ET but-

ton switches back and forth between the two timers; in ET mode

(it stands for “elapsed time,” not the little leathery guy who was

always trying to phone home), the SET/RST button starts and stops

the timer or, when held in, lets you preset it for count-down use,

just like the ones in the comm radios.

Flight Instruction