ATA 34 - NAVIGATION Flashcards
What is an ADF?
Automatic Direction Finder, low frequency, low range, low accuracy
Where does an ADF recieve a signal from?
a signal transmitted from a Non-Directional Beacon (NDB)
Where is the ADF antenna located?
Inbetween the RAD ALT antenas on the first antenna plate on the
bottom the the FWD tail boom.
Where is the ADF reciever?
in the avionic deck
What is VOR?
Very High Frequency Omnidirectional Radio Range
What kind of signals does a VOR ground station transmit?
Radials which also give reference to magnetic north.
What informationdoes an ILS supply?
Glideslope,marker beacon, and localizer
What defines the ILS frequency?
the localizer frequency
How is the Glidslope frequency assigned?
Automatically
What information does the localizer give?
left/right guidance. It defines the centre line.
What information does the Glidslope give?
up/down guidance at approx. 3 degrees
How many NAV receivers are there?
two GTN750’s (on the slant console)
What items are in the VOR system?
two nav receivers, FMS1&FMS2, two VHF antennas, coupler
Where are the VHF antennas?
on both sides of the tail boom
What is a Marker Beacon System?
It’s part of the ILS system, indicating the distance to touch down on the runway.
What frequency do the marker beacons operate at?
75MHz, but different modulation
How are the different marker beacons recognised?
they’re shown in different colours and different audio alerts.
How many Markers can there be? And what are they called?
Three. Outer, Middle, Inner
Where is the marker antenna located?
the lower l/h mid body of the aircraft.
What is DME?
Distance Measuring Equipment
What is the purpose of DME?
To provide and indication of the distance from a ground station to the aircraft.
When is a DME frequency selected?
automatically when a VOR frequency is selected.
How does a DME work?
The DME transmitter (interrogator) in the aircraft sends a signal to the ground. When a ground station receives it, it automatically transmits a reply signal. The time it takes for the signal to be reveived back gives the distance and time to go.
What is slant range error?
the error given with regards to pythagoris thearem of hypotenuse. The distance to a point from altitude is greator than on a horizontal plane.
When does Slant-Range error increase?
the closer an aircraft approaches the station.
What range does the DME provide?
the slant range.
Where is the DME receiver located?
on the avionic deck
Where is the DME antenna?
the r/h lower mid body
What information will the MFD provide from the DME?
frequency, distance, station name and time to go
How many surveillance systems does an ATC use?
Two. Primary providing azimuth and distance of flying echos, and the Secondary Surveillance Radar (SSR) which interrogates the onboard transponder
Interrogated transpoders reply what data?
SQUAWK code set by the crew (MODE A), flight level (MODE C), a 24-bit address, airfract reg, flight ID, altitude, transponder capability and status (air/ground)
Where is the ATC antenna?
lower l/h midy body (behind the marker beacon)
how do you change the transponder from “ground” to “active”?
by unlocking the collective lever
Where does the transponder recieve power?
28v from the AVI ESS BUS 2
Activating the ATC transponder is done how?
Active FMS1/2 switch, press the “ON” function key (selects mode A & S) and unlock the collective. Press “altitude reporting for MODE C
What modes of operation are available on the transponder?
Standby - Transponder powered but not transmiting
ON - MODE A & S
Altitude Reporting - responds on all 3 modes, A, S & C
What is Transpoder Mode A?
Transmits the squawk code only.
What is transponder Mode C?
Transmits the squawk code along with pressure altitude information
What is transponder mode S?
Provides more detailed information, including 24 bit address, a/c reg, flioght ID, altitude, transponder capability, status (air/ground)
How long does it take for a satellite to orbit the earth?
12 hours
How many satellites does it take for GPS reception?
5
What are the 5 satellites called?
RAIM (Receiver Autonomous Integrity Monitoring).
What is the system called that uses GPS?
Global Navigation Satellite System (GNSS)
How many segments is a GPS system divided into?
Three. Control, Space & User
How accurate is GPS?
Up to 15m.
What is more accurate than GPS?
Differential GPS (DGPS).
How accurate is GDPS?
up to 1.5m
What is a Satellite Based Augmentation System (SBAS)?
A system that uses one geostationary satellite that sends delta information to a GPS reciever.
Where is the Delta information from an SBAS calculated?
A ground station.
Where are the GPS (GTN750’s) located in the aircraft?
on the slant console.
How does a Radio Altimeter work?
By Transmitting a radio singnal to the ground and measuring the time delay it takes to reflect and be received back.
How many antennas are in the a/c RadAlt system?
2.
Where are the Rad Alt antennas located?
Bottom of the tail boom. The FWD transmits and the rear recieves.
When is the Rad Alt tested?
during the Pre-Flight test.
How many Pitot-Static systems does the H145 have?
Two independent systems
What is included in the pitot static system?
Two pitot tubes, four static ports, Connection Hoses and an Alternate cabin static pressure selector valve
All pitot and static ports are heated. True or False?
True, both pitot and all 4 static are heated.
Which pitot-static system is the static selector valve connected to?
system #2
What does the static selector valve do?
measures the cabin Px
What is each pitot-static system connected to?
an ADC (1/2)
What are the ADC’s equipped with to check temperture?
A total temperture probe unit (TTPU)
Which pitot-static system is the IESI connected to?
pitot-static system #1
Calculated values from the pitot-static are sent where?
To both ADC’s
What is the use of the TTPU?
To capture the total air temperture so the ADC can then use the data to correct the calculated air data.
Where are the static ports located?
LH and RH side of the fuselage aft deck
Where are the ADC’s installed?
in the L/H and R/H forward bottom structure.
What kind of cable does the AHRS use?
Glass fibre optic
What does the AHRS measure?
altitude and turning & acceleration rates
Where does the data from the AHRS go?
To the AMC’s.
How many AHRS are installed?
Three
What is the purpose of the IESI?
Back up in case of failure of instruments, additional sensor for IMA and for backas SAS.
Where is the IESI powered from?
ESS BUS 2, and if needed by EMER BUS.
After powering up, how long does the three internal rate gyros need for alignment?
110 seconds.
How is the indicated heading adjusted on the stand-by compass?
by two compensation adjustment screws
What power is used in the STNDBY COMPASS?
internal lighting from ESS BUS 2
