Private Pilot | Lesson 7 - Navigation Systems and Equipment
TABLE OF CONTENTS:
7.1 LONGITUDE AND LATITUDE
7.2 USING VOR RADIALS TO DETERMINE LOCATION
7.3 VORS AND VOR TEST FACILITY (VOT)
7.4 GLOBAL POSITIONING SYSTEM
7.5 AUTOMATIC DIRECTION FINDER (ADF)
7.6 VHF/DIRECTION FINDER FACILITY
7.7 AIRCRAFT TRANSPONDER
7.1 Longitude and Latitude
Any location can be pin-pointed by its longitude and latitude. Lines of latitude and longitude are printed on aeronautical charts (e.g., sectional) with each degree subdivided into 60 equal segments, or "minutes." By referring to your sectional chart, the location of your airport can be easily determined by the intersection of lines of latitude and longitude.
Lines of latitude are parallel to the equator; those north of the equator are indicated as 0° to 90° North latitude, those south of the equator are indicated as 0° to 90° South latitude. (As a pilot flying in the US, it's fair to assume that you'll primarily be operating in the Northern latitudes.)
Lines of longitude are lines which extend from the north pole to the south pole. The prime meridian (which passes through Greenwich, England) is 0° longitude with 180° on both the east and west sides of the prime meridian.
Ascent Quick Quiz - 7.1 Longitude and Latitude
Question 1: (Refer to figure 21, area 3.) Determine the approximate latitude and longitude of Currituck County Airport.Answer
Question 2: (Refer to figure 22, area 2.) Which airport is located at approximately 47°39'30"N latitude and 100°53'00"W longitude?
Answer
Question 3: (Refer to figure 22, area 3.) Which airport is located at approximately 47°21'N latitude and 101°01'W longitude?
Answer
Question 4: (Refer to figure 23, area 3.) Determine the approximate latitude and longitude of Shoshone County Airport.
Answer
Question 5: (Refer to figure 27, area 2.) What is the approximate latitude and longitude of Cooperstown Airport?
Answer
7.2 Using VOR Radials to Determine Location
There will be several exam questions that will require you to identify your location based on the intersection of two given VOR radials.
To locate a position based on VOR radials, draw the radials on your chart or on the plastic overlay during the FAA knowledge test.
Remember that radials are FROM the VOR, or leaving the VOR.
Make sure you have located the correct radial on the compass rose before drawing your line. Double-check yourself by counting in 5° or 10° intervals from each of the closest 30° intervals that are numbered and marked with an arrow.
Other FAA exam questions require you to identify your position based upon the indications of a single VOR.
When flying directly from a station, the heading and the radial being flown will correspond (i.e., 360° heading FROM will be the 360° radial).
Ascent Quick Quiz - 7.2 Using VOR Radials to Determine Location
Question 1: (Refer to figure 21.) What is your approximate position on low altitude airway Victor 1, southwest of Norfolk (area 1), if the VOR receiver indicates you are on the 340° radial of Elizabeth City VOR (area 3)?Answer
Question 2: (Refer to figure 24.) What is the approximate position of the aircraft if the VOR receivers indicate the 320° radial of Savannah VORTAC (area 3) and the 184° radial of Allendale VOR (area 1)?
Answer
Question 3: (Refer to figure 25.) What is the approximate position of the aircraft if the VOR receivers indicate the 245° radial of Sulphur Springs VOR-DME (area 5) and the 140° radial of Bonham VORTAC (area 3)?
Answer
Question 4: (Refer to figure 26, area 5.) The VOR is tuned to the Dallas/Fort Worth VORTAC. The omnibearing selector (OBS) is set on 253°, with a TO indication, and a right course deviation indicator (CDI) deflection. What is the aircraft's position from the VORTAC?
Answer
Question 5: (Refer to figure 29, illustration 8.) The VOR receiver has the indications shown. What radial is the aircraft crossing?
Answer
Question 6: (Refer to figure 29 and figure 27, areas 4 and 3.) The VOR is tuned to Jamestown VOR, and the aircraft is positioned over Cooperstown Airport. Which VOR indication is correct?
Answer
Question 7: (Refer to figure 29, illustration 1.) The VOR receiver has the indications shown. What is the aircraft's position relative to the station?
Answer
Question 8: (Refer to figure 29, illustration 3.) The VOR receiver has the indications shown. What is the aircraft's position relative to the station?
Answer
Question 9: (Refer to figure 29 and figure 21, area 3.) The VOR is tuned to Elizabeth City VOR, and the aircraft is positioned over Shawboro. Which VOR indication is correct?
Answer
Question 10: (Refer to figure 25 and figure 29.) The VOR is tuned to Bonham VORTAC (area 3) and the aircraft is positioned over the town of Sulphur Springs (area 5). Which VOR indication is correct?
Answer
7.3 VORs and VOR Test Facility (VOT)
Certain airports have VOR Test Facilities (VOTs). These are facilities that transmit radio signals on certain discrete frequencies, allowing you to check the accuracy of your aircraft's VOR receiver while you are on the ground.
To utilize the VOT simply tune your aircraft's VOR to the specified VOT frequency, and use the OBS knob to center the course deviation indicator needle.

Regardless of your position or heading at the airport, the OBS should read either:
- 180° and TO on the TO/FROM indicator. Or,
- 0° and FROM on the TO/FROM indicator.
NOTE: Accuracy of the VOR must be within ±4°.
Ascent Quick Quiz - 7.3 VORs and VOR Test Facility (VOT)
Question 1: When the course deviation indicator (CDI) needle is centered during an omnireceiver check using a VOR test signal (VOT), the omnibearing selector (OBS) and the TO/FROM indicator should readAnswer
7.4 Global Positioning System
The use of GPS (or, Global Positioning System) is becoming more and more prevalent in general aviation as a means of navigation. Many newer general aviation aircraft come factory-equipped with GPS navigation systems, and every month it seems there is a new portable GPS available on the market.
The Global Positioning System (GPS) is composed of a constellation of 24 satellites, placed in designed orbits that allow for at least five satellites to be in constant line-of-sight by a user anywhere on earth.
However, a GPS receiver needs only four satellites to yield a three-dimensional position (latitude, longitude, and altitude) and time solution.
GPS receivers are able to compute navigational solutions such as distance and bearing to waypoints (e.g., an airport), or groundspeed, etc., by using the airplane's known latitude/longitude (position) and referencing this to a database built into the receiver.
Ascent Quick Quiz - 7.4 Global Positioning System
Question 1: How many satellites make up the Global Positioning System (GPS)?Answer
Question 2: What is the minimum number of Global Positioning System (GPS) satellites that are observable by a user anywhere on earth?
Answer
Question 3: How many Global Positioning System (GPS) satellites are required to yield a three dimensional position (latitude, longitude, and altitude) and time solution?
Answer
7.5 Automatic Direction Finder (ADF)
Another type of navigational instrument found in aircraft is the Automatic Direction Finder, or ADF. The ADF is an instrument that works in conjunction with a ground-based nondirectional beacon, or NDB. The ADF functions simply by always having its need point directly toward the NDB to which the instrument is tuned to.
- For example, if the NDB is directly in front of the airplane, the needle will point straight up.
- If the NDB is directly off the right wing, i.e., 3 o’clock, the needle will point directly to the right.
- If the NDB is directly behind the aircraft, the needle will point straight down, etc.
There are a few specific terms used when referencing navigation or instrument flying by the use of the ADF/NDB. The figure below should help to illustrate these terms. (When working ADF problems, it is often helpful to draw the information given - just like the figure below - to provide a picture of the airplane's position relative to the NDB station.)
- Relative bearing TOthe station is shown by the head of the needle.
- In the figure below, the RB to the station is 220°.
- Relative bearing FROMis given by the tail of the needle.
- In figure below, the RB from the station is 40° (220 – 180).
If you turn right from your present heading to fly to the station, you are adding the number of degrees of turn to your heading.
Remember this equation:
Magnetic Heading + Relative Bearing = Magnetic Bearing TO the station, or
MH + RB = MB (TO)
EXAMPLE:
If the airplane shown above has an MH of 40° and an RB of 220°, the MB (TO) is 260° (40 + 220).
And, the MB (FROM) is 80° (260 – 180).
Now, there are basically two types of ADFs that can be found in general aviation aircraft, the fixed card ADF and the movable card ADF.
With a fixed card ADF, 0° will always be shown at the top of the instrument.
So, on a fixed card ADF the Relative Bearing may be read directly from the card, and it is the Magnetic Bearing that must be calculated using the above formula.
If the MB is given, the MH may be calculated as follows: MB – RB = MH.
With a movable card ADF, magnetic heading (MH) will always be shown at the top of the instrument.
So, on a movable card ADF the MB TO the station may be read directly from the card under the head of the indicator needle. And, MB FROM will be indicated by the tail of the needle.
RB may be calculated as follows: MB - MH = RB.
Ascent Quick Quiz - 7.5 Automatic Direction Finder (ADF)
Question 1: (Refer to figure 30, illustration 1.) Determine the magnetic bearing TO the station.Answer
Question 2: (Refer to figure 30, illustration 2.) What magnetic bearing should the pilot use to fly TO the station?
Answer
Question 3: (Refer to figure 30, illustration 2.) Determine the approximate heading to intercept the 180° bearing TO the station.
Answer
Question 4: (Refer to figure 30, illustration 3.) What is the magnetic bearing FROM the station?
Answer
Question 5: (Refer to figure 30.) Which ADF indication represents the aircraft tracking TO the station with a right crosswind?
Answer
Question 6: (Refer to figure 30, illustration 1.) What outbound bearing is the aircraft crossing?
Answer
Question 7: (Refer to figure 30, illustration 1.) What is the relative bearing TO the station?
Answer
Question 8: (Refer to figure 30, illustration 2.) What is the relative bearing TO the station?
Answer
Question 9: (Refer to figure 30, illustration 4.) What is the relative bearing TO the station?
Answer
Question 10: (Refer to figure 31, illustration 3.) The relative bearing TO the station is
Answer
Question 11: (Refer to figure 31, illustration 1.) The relative bearing TO the station is
Answer
Question 12: (Refer to figure 31, illustration 2.) The relative bearing TO the station is
Answer
Question 13: (Refer to figure 31, illustration 4.) On a magnetic heading of 320°, the magnetic bearing TO the station is
Answer
Question 14: (Refer to figure 31, illustration 5.) On a magnetic heading of 035°, the magnetic bearing TO the station is
Answer
Question 15: (Refer to figure 31, illustration 6.) On a magnetic heading of 120°, the magnetic bearing TO the station is
Answer
Question 16: (Refer to figure 31, illustration 6.) If the magnetic bearing TO the station is 240°, the magnetic heading is
Answer
Question 17: (Refer to figure 31, illustration 7.) If the magnetic bearing TO the station is 030°, the magnetic heading is
Answer
Question 18: (Refer to figure 31, illustration 8.) If the magnetic bearing TO the station is 135°, the magnetic heading is
Answer
7.6 VHF/Direction Finder facility
The VHF/Direction Finder facility is a ground operation that can determine the magnetic direction of an airplane from the station each time the airplane transmits a signal to it. An air traffic controller can then give aid in the form of directional guidance to the aircraft. In order to take advantage of VHF/DF radio reception for assistance in locating a position, an airplane must have both a VHF transmitter and a receiver. The transmitter and receiver are necessary to converse with a ground station having VHF/DF facilities.
In the Airport/Facility Directory the letters "VHF/DF" appearing next to certain airports indicate that the Flight Service Station has VHF/Direction Finding equipment with which to determine your direction from the station.
Ascent Quick Quiz - 7.6 VHF/Direction Finder facility
Question 1: To use VHF/DF facilities for assistance in locating an aircraft's position, the aircraft must have aAnswer
Question 2: The letters VHF/DF appearing in the Airport/Facility Directory for a certain airport indicate that
Answer
7.7 Aircraft Transponder
Aircraft transponders transmit specific codes that allow air traffic controllers to identify and track specific aircraft.
1200 is the standard VFR transponder code. When operating under VFR below 18,000 ft MSL, the transponder code 1200 should be selected, unless otherwise instructed by ATC. Similarly, if ATC advises, "Radar service is terminated," the transponder should be set to code 1200.
The following codes are for use during aircraft emergencies only. Additionally, as they cause certain immediate responses from ATC, when making routine transponder code changes, pilots should avoid inadvertent selection of the following codes.
- 7700 -- General emergency
- 7600 -- Lost radio communications
- 7500 -- Hijacked aircraft
- 7777 -- Military interceptor code
Ascent Quick Quiz - 7.7 Aircraft Transponder
Question 1: When operating under VFR below 18,000 feet MSL, unless otherwise authorized, what transponder code should be selected?Answer
Question 2: If Air Traffic Control advises that radar service is terminated when the pilot is departing Class C airspace, the transponder should be set to code
Answer
Question 3: When making routine transponder code changes, pilots should avoid inadvertent selection of which codes?
Answer
Lesson 7 - Navigation Systems and Equipment eFlash Cards
Lesson 7 - Navigation Systems and Equipment Study Quiz

