THE
PILOT
radio
navigation
ATPL
STUDENT
pilot
resume
all info you need to pass atpl exams
,Radio theory
• Phase: Fraction of one wavelength expressed in degrees from 000 - 360
• Cycle: A complete series of values of a periodical process
• Frequency: Number of oscillations/cycles per second of an electromagnetic wave
• Phase difference: ANGULAR difference between two cycles of equal wavelength
• Wavelength (λ) = Speed of light (m/s) ÷ frequency (Hz)
• SSB: Used in HF & VOLMET, AM
• Modulation: Addition of a low frequency signal onto high frequency carrier wave
• Phase modulation: Used by GPS, Helical antennas as GPS have circular polarization
• Pulse modulation: Radar
• NON A1A modulation/keying: Interrupting carrier wave to break it into dots & dashes does not change
frequency or amplitude
• MSI: Modulation, signal, information
• Keying: Interrupting the carrier wave to break it into dots & dashes
Antennae
• Electrical field E same direction as aerial
• Magnetic field H perpendicular to aerial
• Antennae length = half wavelength (λ)
• POLARIZATION: Orientation of the plane of oscillation of the electrical component E
• AC induced parallel to wire, but remote from it
• First wire radiates energy to space, second wire induces AC
• Flat (Slotted) plate eliminates/generates less side lobes than parabolic
• Helical antennae used by GPS due to circular polarization
• Radar uses one antenna for both transmitting and receiving
• Directional antennas: Loop(ADF), parabolic, slotted planar, helical
• Dipole antennas: Are the simplest. Needs the receiver & transmitter of electrical field on the same
planes
Radio propagation
• Electromagnetic wave : Sky wave, Radio wave: Space wave
• Absorption: Energy taken up by atmosphere
• Attenuation:
- Weakening of the radio wave.
- Lower frequency, greater attenuation. (RANGE)
• Diffraction: Passing/bending over impenetrable obstacles with dimensions close to wavelength
• Reflection: Change in direction of radio wave after reaching a boundary (Used by HF)
• Refraction: Change in direction/bending due to a change in speed, as it passes area of different
electrical conductivity. (SKYWAVES) (Used by HF)
• Interference: Superimposition of two radio waves of same frequency
• Night effect/Fading: Occurs at night, Interference of ground wave with sky wave, Ionospheric
reflection. HF frequency should be reduced at night, higher frequency & higher Ionospheric layer
= larger skip distance
• ONLY HF propagates via SKYWAVE for practical use and the ground wave is really small
Direction finding
• Range = 1.23 x (√Transmitter + √Receiver)
• QUJ: True TO station (To Juliet)
QTE: True FROM station
QDM: Magnetic TO station (To your Mom)
QDR: Magnetic FROM station
, • Provides HOMING, measures RELATIVE TO/AT STATION. Do NOT BANK when using
• Uses METRIC wavelengths, VHF 118MHz – 136MHz, Class A: 2° B: 5° C: 10°
• ATC must have at least 2 VDFs. Military uses UHF
• Multi-path error results in bearing error
• Uses loop & sense antenna
• Night effect: Fluctuating indications
NDB/ADF
• NDB frequency: 190 - 1750 kHz, HECTOMETRIC/KILOMETRIC wavelength
• MH + RB = MB (My hairy red balls make babies) [MB to station aka QDM]
• Power new ÷ Power old = (Range new ÷ range old)2
• ADF/NDB error: +/-5 ° generally
• To double range, power x 4
• Maintaining RB = maintaining CONSTANT TRACK
• RB angle between where I’m heading(AC nose) to where ADF needle is pointing
• True bearing is always given FROM VDF station (QTE)
• NDB/ADF variations at AIRCRAFT
VOR variations at the STATION
• Difference between HOMING & TRACKING
• Range of NDB determined by power & surface (land/water) not affected by aircraft height
Land range = 2 √Power in watts
Sea range = 3 √Power in watts
• BFO circuit: Makes A1A signal identifiable by Morse
• LOCATERS: Used for ILS, different from NDB in operations and power
• EN-ROUTE: Long range, LF A1A
• What does the arrow at the tip of the RMI indicate? QDM
• ERRORS:
- Mountain effect: Reflection (For some reason)
- Night effect/Fluctuations/Fading: Interference of REQUIRED ground wave with sky wave, sky
wave distortion of null, max at dusk & dawn, sky wave reflected from ionosphere (Only for
NDB/ADFs)
- Static interference: Thunderstorms (Most significant)
- Coastal refraction: Higher ALT = Lesser error
- Quadrantal: Refraction of aircraft fuselage
- Absence of failure warning
- Loop null error: When plane of loop is at right angles to direction of transmitter
VOR
• Phase difference = radial from VOR
• RADIAL: Magnetic bearing of aircraft FROM station
• NDB/ADF variations at AIRCRAFT
VOR variations at the STATION
• CVOR signal: Rotates at 30 times/second giving characteristics of 30Hz AM
• DVOR: Uses frequency modulation (FM), more accurate
• Using VOR outside published range, may cause interference from other transmitters
• Quoted accuracy applied at all times
• VOR switches off when there is measured error greater than 1°
• VOR frequency: 108 – 117.95MHz (VHF frequency) , METRIC wavelengths
• VOT: Test VOR
• TVOR: Terminal VOR, Even frequencies e.g. 108.25, 108.45… etc.
• 1 in 60: Angle a = (Distance off track x 60) ÷ distance along track
• Same radial, different distance: Reference & variable both unequal
PILOT
radio
navigation
ATPL
STUDENT
pilot
resume
all info you need to pass atpl exams
,Radio theory
• Phase: Fraction of one wavelength expressed in degrees from 000 - 360
• Cycle: A complete series of values of a periodical process
• Frequency: Number of oscillations/cycles per second of an electromagnetic wave
• Phase difference: ANGULAR difference between two cycles of equal wavelength
• Wavelength (λ) = Speed of light (m/s) ÷ frequency (Hz)
• SSB: Used in HF & VOLMET, AM
• Modulation: Addition of a low frequency signal onto high frequency carrier wave
• Phase modulation: Used by GPS, Helical antennas as GPS have circular polarization
• Pulse modulation: Radar
• NON A1A modulation/keying: Interrupting carrier wave to break it into dots & dashes does not change
frequency or amplitude
• MSI: Modulation, signal, information
• Keying: Interrupting the carrier wave to break it into dots & dashes
Antennae
• Electrical field E same direction as aerial
• Magnetic field H perpendicular to aerial
• Antennae length = half wavelength (λ)
• POLARIZATION: Orientation of the plane of oscillation of the electrical component E
• AC induced parallel to wire, but remote from it
• First wire radiates energy to space, second wire induces AC
• Flat (Slotted) plate eliminates/generates less side lobes than parabolic
• Helical antennae used by GPS due to circular polarization
• Radar uses one antenna for both transmitting and receiving
• Directional antennas: Loop(ADF), parabolic, slotted planar, helical
• Dipole antennas: Are the simplest. Needs the receiver & transmitter of electrical field on the same
planes
Radio propagation
• Electromagnetic wave : Sky wave, Radio wave: Space wave
• Absorption: Energy taken up by atmosphere
• Attenuation:
- Weakening of the radio wave.
- Lower frequency, greater attenuation. (RANGE)
• Diffraction: Passing/bending over impenetrable obstacles with dimensions close to wavelength
• Reflection: Change in direction of radio wave after reaching a boundary (Used by HF)
• Refraction: Change in direction/bending due to a change in speed, as it passes area of different
electrical conductivity. (SKYWAVES) (Used by HF)
• Interference: Superimposition of two radio waves of same frequency
• Night effect/Fading: Occurs at night, Interference of ground wave with sky wave, Ionospheric
reflection. HF frequency should be reduced at night, higher frequency & higher Ionospheric layer
= larger skip distance
• ONLY HF propagates via SKYWAVE for practical use and the ground wave is really small
Direction finding
• Range = 1.23 x (√Transmitter + √Receiver)
• QUJ: True TO station (To Juliet)
QTE: True FROM station
QDM: Magnetic TO station (To your Mom)
QDR: Magnetic FROM station
, • Provides HOMING, measures RELATIVE TO/AT STATION. Do NOT BANK when using
• Uses METRIC wavelengths, VHF 118MHz – 136MHz, Class A: 2° B: 5° C: 10°
• ATC must have at least 2 VDFs. Military uses UHF
• Multi-path error results in bearing error
• Uses loop & sense antenna
• Night effect: Fluctuating indications
NDB/ADF
• NDB frequency: 190 - 1750 kHz, HECTOMETRIC/KILOMETRIC wavelength
• MH + RB = MB (My hairy red balls make babies) [MB to station aka QDM]
• Power new ÷ Power old = (Range new ÷ range old)2
• ADF/NDB error: +/-5 ° generally
• To double range, power x 4
• Maintaining RB = maintaining CONSTANT TRACK
• RB angle between where I’m heading(AC nose) to where ADF needle is pointing
• True bearing is always given FROM VDF station (QTE)
• NDB/ADF variations at AIRCRAFT
VOR variations at the STATION
• Difference between HOMING & TRACKING
• Range of NDB determined by power & surface (land/water) not affected by aircraft height
Land range = 2 √Power in watts
Sea range = 3 √Power in watts
• BFO circuit: Makes A1A signal identifiable by Morse
• LOCATERS: Used for ILS, different from NDB in operations and power
• EN-ROUTE: Long range, LF A1A
• What does the arrow at the tip of the RMI indicate? QDM
• ERRORS:
- Mountain effect: Reflection (For some reason)
- Night effect/Fluctuations/Fading: Interference of REQUIRED ground wave with sky wave, sky
wave distortion of null, max at dusk & dawn, sky wave reflected from ionosphere (Only for
NDB/ADFs)
- Static interference: Thunderstorms (Most significant)
- Coastal refraction: Higher ALT = Lesser error
- Quadrantal: Refraction of aircraft fuselage
- Absence of failure warning
- Loop null error: When plane of loop is at right angles to direction of transmitter
VOR
• Phase difference = radial from VOR
• RADIAL: Magnetic bearing of aircraft FROM station
• NDB/ADF variations at AIRCRAFT
VOR variations at the STATION
• CVOR signal: Rotates at 30 times/second giving characteristics of 30Hz AM
• DVOR: Uses frequency modulation (FM), more accurate
• Using VOR outside published range, may cause interference from other transmitters
• Quoted accuracy applied at all times
• VOR switches off when there is measured error greater than 1°
• VOR frequency: 108 – 117.95MHz (VHF frequency) , METRIC wavelengths
• VOT: Test VOR
• TVOR: Terminal VOR, Even frequencies e.g. 108.25, 108.45… etc.
• 1 in 60: Angle a = (Distance off track x 60) ÷ distance along track
• Same radial, different distance: Reference & variable both unequal
