Navigation Terms - Garmin 500W Series Pilot's Manual & Reference

Navigation Terms

The following navigation terms are used on the
500W-series unit:
WPT 1
ALT (altitude) — Height above mean sea level
(MSL).
BRG (bearing) — The compass direction from your
present position to a destination waypoint.
CAS (calibrated airspeed) — Indicated airspeed
corrected for instrument errors.
CUM (cumulative) — The total of all legs in a flight
plan (such as "cumulative distance").
DIS (distance) — The geodesic path from your pres-
ent position to a destination waypoint.
DTK (desired track) — The desired course between
the active "from" and "to" waypoints.
EFF (efficiency) — A measure of fuel consumption,
190-00357-00_0B 500W Pilot Guide203 203
WPT 2
NORTH
190-00357-00 Rev B
expressed in distance per fuel units (e.g., nautical
miles per gallon).
ENDUR (endurance) — Flight endurance, or total
available flight time based upon available fuel.
EPU (estimated position uncertainty) — A
measure of satellite geometry quality and additional
factors, expressed as a horizontal position error in feet
or meters.
ESA (en route safe altitude) — The recommended
minimum altitude within a ten mile radius of your
course on an active flight plan or direct-to.
ETA (estimate time of arrival) — The estimated
time at which you will reach your destination
waypoint, based upon current speed and track.
ETE (estimated time en route) — The time it will
take to reach the destination waypoint, from present
position, based upon current ground speed.
FF (fuel flow) — The fuel flow rate, expressed in fuel
units per time (e.g., gallons per hour).
FOB (fuel on board) — The total amount of usable
fuel on board the aircraft.
Geodesic — an arc path that follows the shortest dis-
tance along an ellipsoid model of the earth (WGS-84).
A geodesic is more accurate than a "great circle" which
assumes a perfect sphere model of the earth.
GS (ground speed) — The velocity you are travelling
relative to a ground position.
HDG (heading) — The direction an aircraft is
pointed, based upon indications from a magnetic
compass or a properly set directional gyro.
IND (indicated) — Information provided by prop-
erly calibrated and set instrumentation in the aircraft
panel (e.g., "indicated altitude").
12 - MESSAGES
ABBREVIATIONS &
NAV TERMS
203
9/7/2007 3:11:09 PM