BGS post its - RNAV Flashcards
What is the beat frequency oscillator on an ADF used for?
Hearing the IDENT of some NDBs
How many atomic clocks are there on a NAVSTAR GPS satellite?
4
What does a single bright line on an AWR screen mean?
The cathode ray tube is faulty.
What should a controller see for ATS surveillance?
a map overlay
A/C identification and FL
How are antennas on modern AWR stabilised?
with inputs from the A/C attitude system (INS/IRS/VRGU)
What is the path delay of GPS signals in earth atmosphere proportional to?
the inverse of carrier frequency squared
What part of ILSs are protected from interference by FM immunity filters?
the localiser
What is scalloping?
a phenomenon which causes a CDI to deviate from side to side due to signal errors
when on a back course how will OBIs and HSIs sense?
an OBI will always reverse sense but a HSI will sense correctly if front course is set
What kind of nav aid can TACANs provide?
They can provide DME to civil A/C but also VOR to military A/C
What is the full scale deflection on a CDI for ILS localiser and glideslope?
localiser - 2.5deg
glideslope - 0.7deg
what is the minimum number of ground stations to give range & bearing information in DF?
2
How many times and on what frequency will VOR and DME idents be heard per second with VOR/DME colocation?
VOR - 3 times at 1020hz
DME - 1 time at 1350hz
What does the DME display counter rotating about its full range indicate?
It is conducting a range search.
What mode must a SSR unit be in to transmit mode A, C or S?
ALT
(ON is for mode A only)
What is quadrantal error of an ADF caused by?
refraction from A/C fuselage
What can be said about the azimuth and elevation transmitters of a MLS?
they operate on a shared frequency.
What is the coverage of the approach zone for MLS systems?
+/- 40deg of the rwy centre line out to 20nm
What is the coverage of the approach zone in elevation for MLS systems?
0.9deg to 20deg out to 20nm
Where are glidepath antenna located?
at the side off the runway approximately 300m beyond the threshold
What part of EM waves are polarised?
the electrical part.
Are ATC frequencies contained in the navigation database?
no
When does DME interoogation begin?
Once the first pulse paris of the tuned DME have been recieved
Upon losing signal of an SBAS signal (EGNOS) how long would it take for an indication to show up?
6 seconds
what is search the sky mode for GPS?
a procedure that starts after switching on if there is no stored satellite data available.
What additional system does an FMS need to control vertical position?
Autothrottle
What can VDF provide?
QDM or QTE
When will ETOs and ETAs at destination computed by an FMS be correct?
if actual wind = forecast wind
if actual speed = FMC calculated speed
What should the accuracy of GPS be?
13m horizontal
22m vertical
95% of the time
what does the 2000 SSR code mean?
entering the airspace from area where SSR operation has not been required (oceanic)
What kind of modulation do HF and VHF comms broadcasts have?
AM
Out of VHF and HF which one is SSB?
HF
What part of the VHF comms signal contains the information being transmitted?
the sidebands.
What are the order of accuracies for RNAV fixes?
GNSS
IRS/INS
DME/DME
VOR/DME
VOR/VOR
What is the orientation and number of satellites for most accurate position fix?
3 satllites low to the horizon and 1 more directly overhead (tetrahedron)
Are the clocks in GPS constellations synchonised?
no
Are satellite clock time corrections contained in the navigation message sent to A/C from the satellite?
yes
What is FADING?
essentially destructive interference between sky and ground waves due to night effect
What is another way of saying pulse recurrence rate?
pulse recurrence frequency
What affects a primary radars ability to discriminate between targets in azimuth?
beam width
How is the doppler effect used in DVORs?
it is used to create a FM signal as received by an A/C and reduces siting error
What does the MTR equation actually mean?
MTR is the range from LOS
What is the purpose of AWR?
to detect precipitation usually accompanied by turbulence
what is the A/C doing in DME tracking mode?
It is locked onto a DME and transmitting a relatively low number of pulse pairs per second
When saturated, how will a DME decide which aircraft to prioritise?
those with the strongest signals
How are VORTACs represented on the EFIS?
The same way a normal TACAN would be in GNAV
Which DMEs will an FMS auto tune to?
The DMEs providing the best angular position lines for the RNAV system
What is the coverage of GBAS systems?
+/- 35 deg out to 15nm
+/- 10deg out to 20nm
from threshold
What is the datum used for MDA on a non-precision approach when using GPS?
barometric altitude
What are the L1 and L2 frequencies and purposes of NAVSTAR?
L1 - 1575.42MHz - C/A & P (alies)
L2 - 1227.6MHz - P
What can the middle marker of DME be used for?
to indicate the position for a missed approach in a CAT 1 approach during poor vis.
What are the marker distances for DME?
Inner - 100m
Middle - 1000m
Outer - 10km (8km)
What does the gain control knob do on an AWR?
it adjusts the sensitivity of the receiver to achieve optimum target aquisition.
How does MLS minimise multipath errors?
The signal is inturrupted when the scanning beam passes over known obstacles to avoid reflection
How can a failure of VOR systems be recognised on an EFIS display?
The magenta indications are removed.
