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If VOR bearing information is used beyond the published protection range, errors could be caused by...
interference from other transmitters
If the reference phase differs 30° with the variable phase, the radial from the VOR station will be ...
030 Grad
VOR ==> Frequency
VHF Omni directional Radio Range ==> phraseology used with VOR navigation is radial =>
108 - 111.975 MHz ( decimals only ) for T-Vor
111.975 to 117.975 MHz => channel spacing of 50 kHz => 117.95 for en route VOR
VOR stations sends
a) radial
b) station indentification
c) optional voice information => ATIS
Antenna System of VOR
consists of a horizontal dipole antenna ==> horizontal polarisation with an 8-shaped radiation diagram and a poly directional antenna system
to enable an aircraft to esatblish its own bearing from station => two signals are required
a) a variable phase (VP): varies according to aircraft position
b) a reference phase (RP): always the same for any aircraft position
DVOR
more complex antenna system => to increase the antenna baseline which in consequence reduces the effect of terrain-caused radial bends ==> easy to see that the reflected energy of a system with a bigger antenna baseline spreads further than from a small a
The antenna system of a DVOR consists of a centre antenna and an array of about 40 antennas is arranged in a circle, welcher sich dreht ==> This produces
this movement produces a Doppler shift of the frequency ==> the variable phase
VOT
Test VOR ==> the received radial is always 360 => consists of dots or a continuous tone => to check on-board VOR ==> Max. permissible bearing is +/- 4 ==> Muss immer 360 einstellen auf HSI und muss TO und deviation bar in der Mitte
Manual VOR circuit ?
CDI and HSI ==> manually select a course while using VOR system to display angular course deviation and TO/FRON information
Automatic Circuit
automatically provide radial information ?==> corresponds to the aircraft's actual radial
VOR Anzeige immer
MN => Variation AN der VOR Station
(RMI) The angle between lubber line and teh needle tip represents
RB = relative bearing =
Errors abd Accuracy (Genauigkeit)
VOR less subject to errors than NDB ==> mountains effect => Interference caused by reflection = keine optics Verbindung ==> BENDING (aircraft follows an erroneous bearing) AND SCALLOPING (involves sudden changes)
Genauigkeit bei Fehlern VOR
+/- 4 degrees for aggregate error +/-5 degrees for VOR system use eror
2 System failure by VOR
1. compass system failure => red reading flag ==> HSI can still be used as a CDI (nur Kompass geht nicht mehr) 2. VOR system Failure: a red NAV flag
Why is the Doppler effect utilised for DVORs
To increase the antenna baseline and to produce a frequency modulated variable phase
Why is the signal of a VOR monitored by ground monitoring stations?
To increase the integrity of the NAVAID
A loop aerial, as used in the ADF, will
Receive a minimum or null signal from a transmitter when the plane of the loop is at right angles to the direction of the transmitter
The combination of the polar diagrams of the loop and the sense aerial results in
A cardoid polar diagram, having only one null or minimum
A radio beacon has an operational range of 10 NM. By what factor should the transmitter power be increased in order to achieve an operational range of 20 NM?
four
There are two NDBs, one 20 NM inland, and the other 50 NM inland from the coast.
Assuming that the error caused by coastal refraction is the same for both propagations, the extent of the error in a position line plotted by an aircraft that is over water will be:
greater from the beacon that is 50 NM inland
In order to obtain an ADF bearing the...
signal must be received by both the sense and loop aerials
The BFO selector on an ADF receiver is used to:
hear the IDENT of some NDB stations radiating a continuous wave signal
An NDB transmits a signal pattern in the horizontal plane which is ..
omni directional
The ADF reception loop is always used so that the electromotive force (EMF)...
induced is zero
In Europe, most NDBs operate in the frequency band
200 kHz to 526.5 kHz
It is very simple, being required to transmit only a carrier wave and an identification => True or false
true
Some ADFs have a bandwidth control. Consider the following statements and select the one that is correct:
NDB Frequezen in Deutschland
generelle LF/MF => 190 kHz - 1750 kHz ==> Europa 200-526.5 kHz
2 Arten NDB
1. En-route NDB's up to 200 NM=> Extrem power and A1A up to 300 NM 2. Terminal NDBs = Compass Locator = locater Beacon 10-25 NM
Range and power => over water ? wenn man die Range verdoppel will?
R = C * Wurzel (P) C = factor => R verdoppeln => mit dem Factor 4 ==> range over water is greater than the range over land because of the better conductivity of sea water
3 Modulationen von NDB
N0N/A1A N0N/A2A A3E = Broadcasting station
Antennen NDB
a vertically polarized signal with a non-directional pattern ==> Omnidirectional
NDB by day
D-layer is so strong that NDB radio waves are absorbed completely by this layer => NDB radio waves are only propagated with the ground waves
NDB by night
D-layer disappears, the NDB radio waves travel to the higher E- and F-layer, which are able to refract them => ground waves has enough power to overcome the sky waves skip distance, these waves interfere (zusammentreffen) and a change in polarization as well as fading may occur
the loop antennes receiwes when its max. and min.?
max: of teh radio waves energy when the axis of teh coil is perpendicular to the direction of teh station
Min: when teh axis of the coil is pointing towards teh station
3 different stages type ADF
1. real loop type: a navigator turned the loop manually for direction finding
2. goniometer: a dual loop construction ( x-Loop and Y-loop) fixed outside the fuselage => the errors causeb by the fuselage were easier to elimate
3. All electronic type: ADF antenna which contains a dual loop ( X-loop and Y-Loop) ==> an electronic circuit is used to rotate the cardioid pattern continously at 30 Hz => do to continuous rotation an amplitude modulation of the received radio signal occurs
by the all electronic type: Was für ein Diagramm?
cardioid polar diagram => only one null
When is BFO switched on
an audible signal is generated, thus enabling identification of NDB which use N0N/A1A modulation
