FAA Electronic Navigation Exam 2 — Questions and Answers

Question 1: When the course deviation indicator (CDI) needle is centered using a VOR test signal (VOT), the omnibearing selector (OBS) and the TO/FROM indicator should read

180° FROM, only if the pilot is due north of the VOT.
0° TO or 180° FROM, regardless of the pilot’s position from the VOT.
0° FROM or 180° TO, regardless of the pilot’s position from the VOT. (Correct answer)

Correct answer: 0° FROM or 180° TO, regardless of the pilot’s position from the VOT.

A VOR test signal (VOT) transmits a single 360° radial omnidirectionally. When a VOR receiver is tuned to a VOT and the CDI needle is centered, the omnibearing selector (OBS) and the TO/FROM indicator should consistently read either 0° with a FROM indication or 180° with a TO indication. This is because the VOT effectively simulates being on the 360° (or 0°) radial from the station, and this indication is independent of the pilot's physical position relative to the VOT.

Question 2: (Refer to Figure 25, area 5.) The navigation facility at Dallas-Ft. Worth International (DFW) is a

VOR.
VOR/DME. (Correct answer)
VORTAC.

Correct answer: VOR/DME.

Referring to Figure 25, area 5, the navigation facility at Dallas-Ft. Worth International (DFW) is depicted by a hexagon symbol with a square inside. According to standard sectional chart legends, this symbol indicates a VOR/DME (VHF Omnidirectional Range with Distance Measuring Equipment). A VOR/DME provides both bearing information to/from the station and distance information.

Question 3: How many satellites make up the Global Positioning System (GPS)?

25.
22.
24. (Correct answer)

Correct answer: 24.

The Global Positioning System (GPS) is a satellite-based navigation system that consists of a constellation of 24 operational satellites. These satellites orbit the Earth in six different orbital planes, ensuring global coverage and the availability of multiple satellites for accurate positioning at any given time.

Question 4: What is the minimum number of Global Positioning System (GPS) satellites that are observable by a user anywhere on earth?

6.
5. (Correct answer)
4.

Correct answer: 5.

While a minimum of four GPS satellites are required for a three-dimensional position fix, the GPS constellation is designed to ensure that a minimum of five satellites are observable by a user anywhere on Earth at any given time. This redundancy provides improved accuracy and allows for Receiver Autonomous Integrity Monitoring (RAIM), which requires at least five satellites (or four with a barometric altimeter input).

Question 5: How many Global Positioning System (GPS) satellites are required to yield a three dimensional position (latitude, longitude, and altitude) and time solution?

5.
6.
4. (Correct answer)

Correct answer: 4.

To yield a three-dimensional position (latitude, longitude, and altitude) and a precise time solution, a Global Positioning System (GPS) receiver requires signals from a minimum of four satellites. Each satellite provides ranging data, and with four such measurements, the receiver can accurately calculate its unknown position in three dimensions and synchronize its internal clock.

Question 6: (Refer to Legend 1) What symbol would indicate a VORTAC location on an airport?

A hexagon with a dot in the middle.
A runway configuration with a dot. (Correct answer)
A circle with a dot in the center.

Correct answer: A runway configuration with a dot.

On a sectional chart, the symbol for an airport with a hard-surfaced runway is a runway configuration with a dot. Since VORTACs (VOR and TACAN combined navigation facilities) are frequently co-located with airports, identifying this airport symbol is the initial step in locating a VORTAC that might be situated there. The VORTAC's specific symbol (a double-bordered hexagon) would then be found at that airport location, indicating the presence of the navigation aid.

Question 7: (Refer to Legend 1) Which of the symbols depicted with a hexagon represents a VOR-DME?

A hexagon with a dot in the center and enclosed within a square. (Correct answer)
A hexagon with a dot in the middle.
The airport symbol with runway configurations and a dot.

Correct answer: A hexagon with a dot in the center and enclosed within a square.

VOR-DME stations combine the functions of a VOR (Very High Frequency Omnidirectional Range) and DME (Distance Measuring Equipment). According to aviation chart legends, a VOR-DME is specifically depicted as a hexagon with a dot in the center (representing the VOR) enclosed within a square (indicating the co-located DME capability). This distinct symbol helps pilots quickly identify the type of navigational aid available at a specific location.

Question 8: (Refer to Legend 1) A VORTAC station is represented by

A single dot inside a square.
A single dot inside a hexagon.
A single dot inside a hexagon with tabs on three of the sides. (Correct answer)

Correct answer: A single dot inside a hexagon with tabs on three of the sides.

A VORTAC combines a VOR (Very High Frequency Omnidirectional Range) and a TACAN (Tactical Air Navigation) system. On aviation charts, this combined navigational aid is symbolized by a hexagon with a dot in the center, representing the VOR component, and three distinct tabs extending from its sides. These tabs specifically denote the co-located TACAN capability, providing both azimuth and distance information to equipped aircraft.

Question 9: If Receiver Autonomous Integrity Monitoring (RAIM) capability is lost in-flight,

the pilot may still rely on GPS derived altitude for vertical information.
the pilot has no assurance of the accuracy of the GPS position. (Correct answer)
GPS position is reliable provided at least 3 GPS satellites are available.

Correct answer: the pilot has no assurance of the accuracy of the GPS position.

RAIM (Receiver Autonomous Integrity Monitoring) is a crucial function of GPS receivers that verifies the integrity of the GPS signals. If RAIM capability is lost, the GPS receiver cannot detect potential errors in the satellite signals, meaning the pilot has no assurance that the displayed position is accurate. In such a scenario, the GPS system should not be relied upon for navigation, and pilots must revert to other approved navigation methods.

Question 10: 23. A GPS with an expired database may be used

under no circumstances.
only on the ground for taxi.
under VFR flight for situational awareness. (Correct answer)

Correct answer: under VFR flight for situational awareness.

While an expired GPS database cannot be used for IFR flight or for primary navigation where current data is critical, it can still be utilized under Visual Flight Rules (VFR) for basic situational awareness. The underlying GPS receiver still provides position information, and the expired database can offer general geographic context. However, pilots must cross-reference with current charts and other navigation sources, as the data may not reflect the latest changes in airspace, navaids, or obstacles.

Question 11: (Refer to Figure 25, area 5.) The VOR is tuned to the Ranger VORTAC. The omnibearing selector (OBS) is set on 256°, with a TO indication, and a left course deviation indicator (CDI) deflection. What is the aircraft’s position from the VORTAC?

East-Northeast. (Correct answer)
East-Southeast.
West-Northwest.

Correct answer: East-Northeast.

A 'TO' indication on the VOR CDI means the aircraft is currently located on the radial opposite to the one selected, and flying towards the station. If the OBS is set to 256° TO, the aircraft is currently on the 076° radial (256° - 180° = 76°). A left CDI deflection indicates the aircraft is to the right of the selected course. Therefore, if the aircraft is on the 076° radial (East-Northeast of the VORTAC) and the CDI is deflected left, it means the aircraft is to the right of the 256° course, which is consistent with being on the 076° radial.

Question 12: Can a GPS be used as an altimeter?

No, there can be too many errors in the vertical height computations of the GPS to rely on it as an altimeter. (Correct answer)
Yes, but only if a barometric altimeter is available as a backup.
Yes.

Correct answer: No, there can be too many errors in the vertical height computations of the GPS to rely on it as an altimeter.

While GPS receivers can provide altitude information, this 'GPS altitude' is based on the WGS-84 ellipsoid model, which differs significantly from mean sea level (MSL) and local barometric pressure. Barometric altimeters, calibrated to local pressure settings, provide a more accurate and reliable indication of height above terrain or sea level for aviation purposes. The vertical accuracy of GPS is generally less precise than its horizontal accuracy, making it unsuitable as a primary altimeter.

Question 13: When the CDI needle is centered during an airborne VOR check, the omnibearing selector and the TO/FROM indicator should read

0° TO, only if you are due south of the VOR.
within 4° of the selected radial.
within 6° of the selected radial. (Correct answer)

Correct answer: within 6° of the selected radial.

FAA regulations (14 CFR Part 91.171) specify the acceptable tolerances for VOR equipment checks. For an airborne VOR check, the indicated bearing must be within plus or minus 6 degrees of the selected radial when the CDI needle is centered. This tolerance ensures the VOR receiver is functioning accurately enough for safe navigation.

Question 14: What entry must the pilot doing the VOR functioning check make in the aircraft log or other permanent record?

The date, place, satisfactory or unsatisfactory, and signature.
The date, place, bearing error, and signature. (Correct answer)
The date, frequency of VOR or VOT, number of flight hours since last check, and signature.

Correct answer: The date, place, bearing error, and signature.

According to FAA regulations (14 CFR Part 91.171), after conducting a VOR operational check, the pilot must make a specific entry in the aircraft logbook or other permanent record. This entry must include the date of the check, the place where the check was performed, the bearing error observed (or a statement that it was satisfactory), and the pilot's signature. This documentation ensures compliance and provides a record of the VOR's serviceability.

Question 15: When operating a plane with an electronic flight display, something goes wrong with the air data computer. What instrument is affected?

Airspeed indicator. (Correct answer)
Attitude indicator.
ADS-B in capability.

Correct answer: Airspeed indicator.

The Air Data Computer (ADC) is a vital component in modern electronic flight displays (EFIS). It processes raw data from the pitot-static system, including pitot pressure, static pressure, and outside air temperature. This processed information is then used to calculate and display critical flight parameters such as airspeed, altitude, and vertical speed. Therefore, a malfunction in the ADC would directly impact the accuracy and availability of the airspeed indicator.

Question 16: How long would it take to complete a 360° turn if a standard rate turn were maintained?

3 minutes.
1 minute.
2 minutes. (Correct answer)

Correct answer: 2 minutes.

A standard rate turn is defined as a turn that changes the aircraft's heading by 3 degrees per second. To complete a full 360-degree turn at this rate, you would divide 360 degrees by 3 degrees per second, which equals 120 seconds. 120 seconds is equivalent to 2 minutes.

Question 17: What should you take into account before utilizing a handheld GPS for VFR navigation?

All throughout the flight, RAIM capability will be maintained.
Even if the database is outdated, the waypoints will still be correct.
Without warning, position accuracy may deteriorate. (Correct answer)

Correct answer: Without warning, position accuracy may deteriorate.

Handheld GPS units, especially those not certified for aviation, may lack advanced features like RAIM (Receiver Autonomous Integrity Monitoring) or have less robust antennas, making them susceptible to sudden and unannounced degradation of position accuracy. Factors like satellite geometry, signal blockage, or atmospheric conditions can cause accuracy to drop significantly without the pilot being immediately aware. Therefore, pilots must always be prepared for potential accuracy issues and cross-reference with other navigation methods.

Question 18: Please see Figure 42. Which OMNI signal would you get for flight 8?

W. (Correct answer)
T.
V.

Correct answer: W.

To determine the OMNI signal for Flight 8, one would refer to Figure 42 (not provided) to identify the aircraft's position relative to the VOR station. The OMNI signal refers to the specific radial the aircraft is currently located on. If Flight 8 is depicted on the 270-degree radial from the VOR, then the OMNI signal would be 'W' for West.

FAA Electronic Navigation Exam 2

When the course deviation indicator (CDI) needle is centered using a VOR test signal (VOT), the omnibearing selector (OBS) and the TO/FROM indicator should read