Communication and Navigation Systems Practice Test

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• In GPWS described operation, which type of altitude measurement is used to determine height above the ground?
• For checking ELT function during maintenance, which procedure is appropriate?
• Which statement about NMEA 0183 sentence types is true?
• What is the standard axis count for a fully integrated autopilot?
• How are INS and GNSS integrated in navigation systems?
• Static dischargers help eliminate radio interference by dissipating static electricity into the atmosphere at what current levels?
• If fewer satellites are visible or geometry is poor, Dilution of Precision (DOP) is:
• Which statement correctly relates antenna gain, directivity, and efficiency?
• The purpose of a glideslope system is to
• The sensing device in an autopilot responds to which relationship?
• Part of the ADF system used on aircraft includes
• When installing a DME antenna, it should be aligned with which part of the airplane?
• Which component is an altitude encoder used with transponders?
• After ADIF antenna installation, which procedure must be completed to ensure accurate function?
• In BPSK over AWGN, how does BER change with Eb/N0?
• What is a Low-Noise Amplifier (LNA) and why is it critical?
• Doppler measurements contribute to estimating:
• What is the approximate drag load on an antenna with a frontal area of 0.125 square feet at 225 mph?
• A fully integrated autopilot typically controls the aircraft about how many axes?
• How is tropospheric delay modeled and mitigated?
• Doublers in antenna installations are used to
• What is Receiver Autonomous Integrity Monitoring (RAIM) and why is it important for GNSS integrity?
• Which statement correctly describes the difference between the GPS L1 C/A signal and the L2P(Y) signal?
• During an aircraft inspection, how may the operation of an installed ELT be verified?
• The autopilot elevator channel affects which flight parameter most directly?
• Which antenna is used for VOR and Localizer signals?
• Why fuse GNSS with INS for robust navigation?
• A DME antenna should be located in a position on the aircraft that will
• What is the role of a flight management computer?
• Which of the following is a loop sense antenna?
• Which device is typically used to supply attitude information required by the autopilot to maintain stable flight?
• In aerodynamic terms, drag on a surface is proportional to which of the following (assuming area and Cd are constant)?
• Which multiple-access scheme uses unique spreading codes to allow simultaneous users on a shared channel?
• What is the effect of polarization mismatch on GNSS signal reception?
• Why is GNSS reception challenging indoors and what techniques help?
• Which statement accurately describes the signaling architecture difference between GLONASS and GPS?
• After installing an automatic direction finding antenna, which procedure must be completed to ensure accurate function?
• The ELT activation axis is along which axis of the aircraft?
• What is a VOR and its principle in aviation navigation?
• The VOR antenna is typically located on the exterior of a light aircraft in which position?
• In Instrument Landing System, what does the localizer provide?
• How do carrier tracking and code tracking loops operate in GNSS receivers?
• A transponder responds to ground-based interrogations by
• Which system counteracts Dutch roll, a yawing and rolling oscillation common in swept-wing aircraft?
• Which autopilot component is associated with controlling aircraft pitch attitude?
• The preferred location of a VOR antenna on light aircraft is on which part of the airplane?
• When evaluating the installation of a rigid antenna on the vertical stabilizer, which issues should be considered?
• BeiDou's B1I and B2I signals belong to which GNSS system?
• What is the main purpose of a servo in an autopilot system?
• Which modulation technique modulates the carrier phase?
• A typical GNSS receiver front-end architecture includes:
• Which issues are the primary concerns for a rigid antenna mounted on the vertical stabilizer?
• What is ILS and how does it help approach?
• When must the radio station license be displayed in an aircraft equipped with a two-way radio?
• When operationally checking an autopilot system on the ground, after the aircraft's main power has been switched on, the autopilot should be engaged:
• How do dual-frequency GNSS receivers estimate ionospheric delay?
• Which statement correctly describes Galileo and BeiDou signal bands and the capability for dual-frequency operation?
• The correct fastening method for an installed antenna ensures what structural consideration?
• What are RTK corrections and how are they delivered?
• In the landing configuration, GPWS typically monitors which of the following inputs?
• When must the ELT battery be replaced (excluding reading the replacement date)?
• In RTK GNSS, why is a reference station used?
• Which channel of an autopilot detects changes in pitch attitude of an aircraft?
• An emergency locator transmitter (ELT) is normally activated by an inertial switch when subjected to a force of prescribed intensity and duration. It must activate when the force is applied along which axis?
• A gasket or sealant is used between the antenna mast and fuselage skin to prevent the entry of
• Where is the battery replacement date visually indicated on an ELT?
• Which statement about GPS time and UTC is true?
• When fastening an antenna installation, what is the purpose?
• With respect to an aerial installation, where is the strongest signal generally found?
• In a post-install ELT test, what action should you perform?
• Which statement best describes the role of bonding jumpers in radio installations?
• Which autopilot component applies torque to the control surfaces of an aircraft?
• Real-Time Kinematic (RTK) achieves centimeter-level accuracy by:
• How should an antenna be fastened to satisfy proper installation?
• Which material is used as a gasket between the antenna mast and fuselage to seal against moisture?
• What is the correct fastening guideline for an installed antenna?
• Which component is primarily responsible for converting autopilot commands into mechanical movement of the aircraft’s control surfaces?
• For a given antenna, where is the strongest signal typically located?
• Which signaling concept does GPS primarily use to allow multiple satellites to be received on the same frequency?
• Doublers are used when antennas are installed to
• DGPS correction delivery in GNSS is typically accomplished how?
• Which statement accurately describes GPS time and UTC with respect to leap seconds?
• After installing an automatic direction finding antenna, which component must be calibrated?
• What is RTCM used for in GNSS?
• In which control element of an autopilot system is an attitude indicator?
• In general, the purpose of an aircraft transponder is to
• In GNSS, which statement best describes carrier-phase measurements?
• To verify ELT operation during inspection, what sequence should be followed?
• Forward of the CG limit, the addition of avionics and associated antenna systems will affect which airplane characteristic?
• What is the main reason for ensuring the DME antenna is not blanked by the wing during banked flight?
• Where should an aircraft antenna installation be grounded?
• Which device is commonly described as the sensing element providing attitude information to an autopilot system’s guidance?
• Explain which polarization GNSS uses and why it matters.
• What is channel coding and how do convolutional and turbo codes improve reliability?
• Which antenna is typical for DME?
• Which statement describes coherent demodulation?
• Which items are typically included in a link budget?
• VHF signals are commonly used in aviation for which pair of functions?
• How can the battery replacement date for an emergency locator transmitter (ELT) be verified?
• What is the difference between satellite ephemeris and almanac?
• The installation of an automatic direction finding antenna requires calibration of which part?
• What is the primary purpose of an autopilot?
• True or false: Bonding radio equipment to the aircraft reduces interference from static charges.
• Which of the following statements is true about forward avionics placement?
• An emergency locator transmitter (ELT) battery must be capable of furnishing power for signal transmission for at least how many hours?
• Which item needs calibration after adding an automatic direction finding antenna?
• Where is the preferred location of the ELT installed on an aircraft?
• What component is the sensing device in an electromechanical autopilot system?
• Ionospheric delay in GNSS is mitigated by:
• When bending coaxial cable, the bend radius should be at least
• Which action is correct during ground autopilot checks?
• Static discharge wicks on aircraft serve what purpose?
• What is the main reason to secure coaxial cable along its length?
• In GNSS, which statement best describes carrier-phase measurements?
• According to Shannon's capacity formula, what happens to channel capacity as bandwidth increases at fixed SNR?
• In a GNSS link budget, what does Lpath represent?
• For BPSK over AWGN, which expression correctly describes the bit error rate as a function of Eb/N0?
• In GNSS, Doppler measurements are used to determine:
• VHF signals are commonly used in
• For an ELT, which method is used to verify the battery replacement date?
• What is the reason one antenna can serve multiple bands in light aircraft?
• Which factors influence Time to First Fix (TTFF) in a GNSS receiver?
• What is the primary role of PN sequences in spread-spectrum systems?
• Dilution of Precision (DOP) is a measure of satellite geometry affecting position error. A lower DOP value indicates:
• When mounting any antenna, what is the critical reason for securing it?
• The autopilot's aileron input is nullified by which type of signal?
• Real-Time Kinematic (RTK) achieves centimeter-level accuracy by:
• Why is impedance matching important in RF systems?
• What is the role of a Kalman filter in navigation systems?
• Which condition triggers ELT battery replacement, aside from reading the replacement date?
• Which statement correctly describes Precise Point Positioning (PPP) relative to RTK?
• In a link budget, which quantity represents the minimum detectable signal at the receiver?
• Which statement about spread-spectrum systems is true?
• What is a dipole antenna?
• What is the role of a phase-locked loop in a receiver?
• In OFDM, how does the scheme cope with multipath environments?
• If an antenna is blanked by the wing, what is the likely effect on signal reception?
• When installing coaxial cable, it should be secured firmly along its entire length at what interval?
• What principle describes the sensing device used in an autopilot system?
• How is a GNSS link budget expressed and what do the terms represent?
• If an autopilot changes the aircraft’s attitude to correct an error and the control surfaces are returned to streamline by the time the aircraft has reached the correct position, what is the result?
• Which statement correctly describes Precise Point Positioning (PPP) relative to RTK?
• During inspection, what is the method to verify ELT operation?
• What is the role of RF filters in a receiver front-end?
• Which device is typically responsible for monitoring flight parameters and performing autopilot functions on modern large aircraft?
• Dilution of Precision (DOP) is a metric of satellite geometry affecting position error. A lower DOP value indicates:
• Multipath in GNSS refers to:
• ADF system commonly uses which type of antennas?
• In autopilot sensing, which description best describes the sensing element's operating principle?
• If autopilot corrections are made and the aircraft stabilizes as the surfaces streamline during approach, what is the outcome?
• What is the main decoding mechanism behind turbo codes?
• An aircraft antenna installation must be grounded to which structure?
• What is Orthogonal Frequency Division Multiplexing (OFDM) and why is it used in modern digital communication?
• Which statement best defines bandwidth in a communications channel?
• What is the primary purpose of a GNSS link budget equation?
• On modern large aircraft, which electronic device typically monitors flight parameters and performs autopilot functions?
• What is the term for the yawing and rolling oscillation that a yaw damper system counters in swept-wing aircraft?
• What clearance from the seat bottom is required when installing radio equipment under a seat?
• Which component provides manual maneuverability of the aircraft while the autopilot is engaged?
• Which property of PN sequences is most beneficial in spread-spectrum communications?
• Bonding radio equipment to the aircraft provides a low-impedance ground and minimizes interference from static charges. Which of the following best describes this practice?
• In autopilot systems, which device is primarily responsible for converting operational commands into physical movement of the control surfaces?
• What is Differential GPS (DGPS) and how does it improve accuracy?
• Satellite-Based Augmentation System (SBAS) provides which services?
• (1) Use solder to attach bonding jumpers on radio equipment. (2) Radio equipment is bonded to the aircraft in order to provide a low-impedance ground and to minimize radio interference from static electrical charges. Regarding the above statements, which is true?
• What is the primary purpose of Receiver Autonomous Integrity Monitoring (RAIM) in GNSS?
• Why are relativistic effects important for GPS satellite clocks?
• The approximate drag load on an antenna with a frontal area of 0.137 ft² installed on an aircraft at 275 mph is which value?
• What is NMEA 0183 used for in GNSS receivers?
• What is the far-field condition for antennas in terms of the largest dimension D and wavelength λ?
• What are the typical mitigations for GPS jamming and spoofing?
• Under what condition is a U.S. resident NOT required to hold an FCC Restricted Radio Telephone Operator Permit to operate two-way aircraft VHF radio equipment?
• The elevator channel of an autopilot controls the aircraft about which axis of rotation?
• What is DME and how does it work?
• In an autopilot system, which signal cancels or nullifies the input command to the ailerons?
• What does the 'P(Y)' designation indicate on the GPS L2 signal?
• One antenna can be used for the radio range and standard broadcast bands in light aircraft because
• What is the purpose of the localizer in instrument landing guidance?
• What is the function of a zenith tropospheric delay mapping function in GNSS processing?
• What component protects installed radio equipment from damage due to jolts and vibration?