TACAN Flashcards
What frequency does TACAN use?
UHF
What does TACAN provide?
High accuracy bearing and distance to or from a station utilising DME equipment.
What are the two separate but related systems for TACAN?
- DME
- Bearing measuring equipment.
What are TACAN radials?
Magnetic bearings from a station
How many fixed TACANs are there in Australia?
11
What information does the TACAN navigation system provide?
1) Magnetic radial from the selected TACAN station
2) Relative bearing to the selected TACAN station
3) Course Deviation
4) To-from indication
5) Coverage from 5,000 ft is 60 NM, from FL 200 is 180 NM.
6) Aural identification of the TACAN station transmitted every 37.5 seconds
What does the TACAN ground station comprise of?
1) A cylindrical tower with a domed crown
2) DME array at the base, sometimes enclosed within a shelter.
What does the inner cylinder carry?
A reflector
What does the outer cylinder carry?
Nine directors, which rotate together at 15 revs per second.
What is the theory of operation of the TACAN?
- TACAN sends out one Primary Reference Burst and 9 Secondary reference bursts during one revolution of the outer cylinder.
- From this, an accurate radial can be determined.
What does the external aircraft TACAN system comprise?
1) Antenna
2) Transmitter
3) Dual Receivers
What does the A/C antenna do?
Operates at similar frequencies and has a similar function
What does the transmitter do?
Interrogates the DME
What do the dual receivers do?
Process the TACAN pulse pairs and ensure correct signal spacing
What is used to select the TACAN mode of operation on the PC-21?
UFCP
Does TACAN use frequencies or channels ?
Channels
What is used as the primary TACAN display?
- The HSI
- A desired radial can be selected using the course knob and the relative position of the TACAN aid displayed used the Bearing pointers.
How many channels are there on the TACAN system?
252 channels
What are the limitations of the TACAN navigations system?
1) No voice transmission capability
2) Interrogation from a maximum of 100 aircraft
3) LOS operations
4) Limited Range
5) Azimuth Cone of Confusion
6) Shielding by other A/C/ terrain
7) Slant range error when overhead the TACAN.
What are the range limits of TACAN?
- 60 NM for A/C < 5000 ft
- 180 for A/C operating at 20,000 ft.
What is the Azimuth Cone of Confusion?
- The space where TACAN azimuth information is not available which varies from 70 to 100 deg wide.
- Cone is about 15 NM across at 40,000 ft.
What is a TACAN check board?
- Displays information about the TACAN relative to A/C position near the holding point for each of the runways
- Allows the pilot to check the accuracy of TACAN equipment prior to getting airborne.
What does A-A mode provide for the TACAN?
Distance between A/C when flying in formation.
