Avionics News May 2023 - 46

series
B Y
T H O M A S
I N M A N
R-NAV
D
uring the last two months in this Theory
& Practice column, we covered VOR and
DME. When used together, pilots can use
them to determine bearing and distance to a navigation
station. Although VOR stations and DME stations can be
located at airports, most are not. Furthermore, following
airways between various ground-based navigation aids
creates a zigzagging, inefficient route across the country.
Pilots would prefer to navigate to any location within
an area. Thus, engineers developed a system known as
area navigation, or R-NAV for short. In today's world,
satellite navigation is the preferred method of R-NAV,
since the area covered is the entire Earth; however, in
cases where satellite navigation is not available, R-NAV
based on VOR and DME provides the capabilities.
When discussing R-NAV based on VOR and DME,
keep in mind the area is that served by a particular
VOR/DME or VORTAC station. For flights longer than
50 nautical miles, the pilot may need to change the
navigation frequency. On extremely long flights, the pilot
will need to change frequencies multiple times.
R-NAV works using trigonometry. One of the first
principles learned by trigonometry students is if one
46 avionics news * may 2023
angle and two sides of a triangle are known, then the
final side and the other two angles can be calculated.
This is how R-NAV works, and the system is convenient
because it makes these calculations constantly in real
time. Furthermore, the solutions to the calculations
are presented to the pilot in distance/bearing format,
presentable on a CDI, HSI, or moving map display.
It is worth mentioning the fact that some flight
management systems have the capability of using side/
side/side trigonometry. They do this by scanning DME
and TACAN stations.
To understand how an R-NAV works, we can examine
some easy to understand triangles in the context of
a flight. Please refer to Figure 1. In this example, an
aircraft is flying 10 NM west of a VORTAC station. The
VOR and DME on board the aircraft would measure this
and would show a centered indication at 270 degrees
from, and 10 NM. For purposes of discussion, we call
this the measured side of a triangle.
The pilot wants to navigate to a point 10 NM north
of the VORTAC, perhaps to an airport at that location.
We call this location a waypoint, and we define it by its
distance and radial in relation to the VORTAC. In this

Avionics News May 2023

Table of Contents for the Digital Edition of Avionics News May 2023

Avionics News May 2023 - Intro
Avionics News May 2023 - Cover1
Avionics News May 2023 - Cover2
Avionics News May 2023 - 1
Avionics News May 2023 - 2
Avionics News May 2023 - 3
Avionics News May 2023 - 4
Avionics News May 2023 - 5
Avionics News May 2023 - 6
Avionics News May 2023 - 7
Avionics News May 2023 - 8
Avionics News May 2023 - 9
Avionics News May 2023 - 10
Avionics News May 2023 - 11
Avionics News May 2023 - 12
Avionics News May 2023 - 13
Avionics News May 2023 - 14
Avionics News May 2023 - 15
Avionics News May 2023 - 16
Avionics News May 2023 - 17
Avionics News May 2023 - 18
Avionics News May 2023 - 19
Avionics News May 2023 - 20
Avionics News May 2023 - 21
Avionics News May 2023 - 22
Avionics News May 2023 - 23
Avionics News May 2023 - 24
Avionics News May 2023 - 25
Avionics News May 2023 - 26
Avionics News May 2023 - 27
Avionics News May 2023 - 28
Avionics News May 2023 - 29
Avionics News May 2023 - 30
Avionics News May 2023 - 31
Avionics News May 2023 - 32
Avionics News May 2023 - 33
Avionics News May 2023 - 34
Avionics News May 2023 - 35
Avionics News May 2023 - 36
Avionics News May 2023 - 37
Avionics News May 2023 - 38
Avionics News May 2023 - 39
Avionics News May 2023 - 40
Avionics News May 2023 - 41
Avionics News May 2023 - 42
Avionics News May 2023 - 43
Avionics News May 2023 - 44
Avionics News May 2023 - 45
Avionics News May 2023 - 46
Avionics News May 2023 - 47
Avionics News May 2023 - 48
Avionics News May 2023 - 49
Avionics News May 2023 - 50
Avionics News May 2023 - 51
Avionics News May 2023 - 52
Avionics News May 2023 - 53
Avionics News May 2023 - 54
Avionics News May 2023 - 55
Avionics News May 2023 - 56
Avionics News May 2023 - 57
Avionics News May 2023 - 58
Avionics News May 2023 - 59
Avionics News May 2023 - 60
Avionics News May 2023 - 61
Avionics News May 2023 - 62
Avionics News May 2023 - 63
Avionics News May 2023 - 64
Avionics News May 2023 - Cover3
Avionics News May 2023 - Cover4
https://www.nxtbook.com/allen/avne/60-10
https://www.nxtbook.com/allen/avne/60-9
https://www.nxtbook.com/allen/avne/60-8
https://www.nxtbook.com/allen/avne/60-7
https://www.nxtbook.com/allen/avne/60-6
https://www.nxtbook.com/allen/avne/60-5
https://www.nxtbook.com/allen/avne/60-4
https://www.nxtbook.com/allen/avne/60-3
https://www.nxtbook.com/allen/avne/60-2
https://www.nxtbook.com/allen/avne/60-1
https://www.nxtbook.com/allen/avne/59-12
https://www.nxtbook.com/allen/avne/59-11
https://www.nxtbook.com/allen/avne/59-10
https://www.nxtbook.com/allen/avne/59-9
https://www.nxtbook.com/allen/avne/59-8
https://www.nxtbook.com/allen/avne/59-7
https://www.nxtbook.com/allen/avne/59-6
https://www.nxtbook.com/allen/avne/59-5
https://www.nxtbook.com/allen/avne/59-4
https://www.nxtbook.com/allen/avne/59-3
https://www.nxtbook.com/allen/avne/59-2
https://www.nxtbook.com/allen/avne/59-1
http://www.brightcopy.net/allen/avne/58-12
http://www.brightcopy.net/allen/avne/58-11
http://www.brightcopy.net/allen/avne/58-10
http://www.brightcopy.net/allen/avne/58-9
http://www.brightcopy.net/allen/avne/58-8
http://www.brightcopy.net/allen/avne/58-7
http://www.brightcopy.net/allen/avne/58-6
http://www.brightcopy.net/allen/avne/58-5
http://www.brightcopy.net/allen/avne/58-4
http://www.brightcopy.net/allen/avne/58-3
http://www.brightcopy.net/allen/avne/58-2
http://www.brightcopy.net/allen/avne/58-1
http://www.brightcopy.net/allen/avne/57-12
http://www.brightcopy.net/allen/avne/57-11
http://www.brightcopy.net/allen/avne/57-10
http://www.brightcopy.net/allen/avne/57-9
http://www.brightcopy.net/allen/avne/57-8
http://www.brightcopy.net/allen/avne/57-7
http://www.brightcopy.net/allen/avne/57-6
http://www.brightcopy.net/allen/avne/57-5
http://www.brightcopy.net/allen/avne/57-4
http://www.brightcopy.net/allen/avne/57-3
http://www.brightcopy.net/allen/avne/57-2
http://www.brightcopy.net/allen/avne/57-1
http://www.brightcopy.net/allen/avne/56-12
http://www.brightcopy.net/allen/avne/56-11
http://www.brightcopy.net/allen/avne/56-10
http://www.brightcopy.net/allen/avne/56-9
http://www.brightcopy.net/allen/avne/56-8
http://www.brightcopy.net/allen/avne/56-7
http://www.brightcopy.net/allen/avne/56-6
http://www.brightcopy.net/allen/avne/56-5
http://www.brightcopy.net/allen/avne/56-4
http://www.brightcopy.net/allen/avne/56-3
http://www.brightcopy.net/allen/avne/56-2
http://www.brightcopy.net/allen/avne/56-1
http://www.brightcopy.net/allen/avne/55-12
http://www.brightcopy.net/allen/avne/55-11
http://www.brightcopy.net/allen/avne/55-10
http://www.brightcopy.net/allen/avne/55-9
http://www.brightcopy.net/allen/avne/55-8
http://www.brightcopy.net/allen/avne/55-7
http://www.brightcopy.net/allen/avne/55-6
http://www.brightcopy.net/allen/avne/55-5
http://www.brightcopy.net/allen/avne/55-4
http://www.brightcopy.net/allen/avne/55-3
http://www.brightcopy.net/allen/avne/55-02
http://www.brightcopy.net/allen/avne/55-01
http://www.brightcopy.net/allen/avne/54-12
http://www.brightcopy.net/allen/avne/54-11
http://www.brightcopy.net/allen/avne/54-10
http://www.brightcopy.net/allen/avne/54-9
http://www.brightcopy.net/allen/avne/54-8
http://www.brightcopy.net/allen/avne/54-7
http://www.brightcopy.net/allen/avne/54-6
http://www.brightcopy.net/allen/avne/54-5
http://www.brightcopy.net/allen/avne/54-4
http://www.brightcopy.net/allen/avne/54-3
http://www.brightcopy.net/allen/avne/54-2
http://www.brightcopy.net/allen/avne/54-1
http://www.brightcopy.net/allen/avne/53-12
http://www.brightcopy.net/allen/avne/53-11
http://www.brightcopy.net/allen/avne/53-10
http://www.brightcopy.net/allen/avne/53-9
http://www.brightcopy.net/allen/avne/53-8
http://www.brightcopy.net/allen/avne/53-7
http://www.brightcopy.net/allen/avne/53-6
http://www.brightcopy.net/allen/avne/53-5
http://www.brightcopy.net/allen/avne/53-4
http://www.brightcopy.net/allen/avne/53-3
http://www.brightcopy.net/allen/avne/53-2
http://www.brightcopy.net/allen/avne/53-1
http://www.brightcopy.net/allen/avne/52-12
http://www.brightcopy.net/allen/avne/52-11
http://www.brightcopy.net/allen/avne/52-10
http://www.brightcopy.net/allen/avne/52-9
http://www.brightcopy.net/allen/avne/52-8
https://www.nxtbook.com/allen/avne/52-7
https://www.nxtbook.com/allen/avne/52-6
https://www.nxtbook.com/allen/avne/52-5
https://www.nxtbook.com/allen/avne/52-4
https://www.nxtbook.com/allen/avne/52-3
https://www.nxtbook.com/allen/avne/52-2
https://www.nxtbook.com/allen/avne/52-1
https://www.nxtbook.com/allen/avne/51-12
https://www.nxtbook.com/allen/avne/51-11
https://www.nxtbook.com/allen/avne/51-10
https://www.nxtbook.com/allen/avne/51-9
https://www.nxtbook.com/allen/avne/51-8
https://www.nxtbook.com/allen/avne/51-7
https://www.nxtbook.com/allen/avne/51-6
https://www.nxtbook.com/allen/avne/51-5
https://www.nxtbook.com/allen/avne/51-4
https://www.nxtbook.com/allen/avne/51-3
https://www.nxtbook.com/allen/avne/51-2
https://www.nxtbook.com/allen/avne/51-1
https://www.nxtbook.com/allen/avne/50-12
https://www.nxtbook.com/allen/avne/50-11
https://www.nxtbook.com/allen/avne/50-10
https://www.nxtbook.com/allen/avne/50-9
https://www.nxtbook.com/allen/avne/50-8
https://www.nxtbook.com/allen/avne/50-7
https://www.nxtbook.com/allen/avne/50-6
https://www.nxtbook.com/allen/avne/50-5
https://www.nxtbook.com/allen/avne/50-4
https://www.nxtbook.com/allen/avne/50-3
https://www.nxtbook.com/allen/avne/50-2
https://www.nxtbook.com/allen/avne/50-1
https://www.nxtbook.com/allen/avne/49-12
https://www.nxtbook.com/allen/avne/49-11
https://www.nxtbook.com/allen/avne/49-10
https://www.nxtbook.com/allen/avne/49-9
https://www.nxtbook.com/allen/avne/49-8
https://www.nxtbook.com/allen/avne/49-7
https://www.nxtbook.com/allen/avne/49-6
https://www.nxtbook.com/allen/avne/49-5
https://www.nxtbook.com/allen/avne/49-4
https://www.nxtbook.com/allen/avne/49-3
https://www.nxtbook.com/allen/avne/49-2
https://www.nxtbook.com/allen/avne/49-1
https://www.nxtbook.com/allen/avne/48-12
https://www.nxtbook.com/allen/avne/48-11
https://www.nxtbookmedia.com