General / Misc Equipment stuff (EQMT) Flashcards
What is CNS equipment?
Communication, navigation and surveillance equipment. Basically all equipment used by air traffic services.
What is the difference between navigation and surveillance equipment?
Navigation equipment is for telling the pilots where they are, which way they’re pointing, how fast they’re going, etc. Surveillance is for telling people on the ground basically all of the same stuff without having to ask.
What are the minima for CAT I, II, IIIA, IIIB and IIIC approaches?
CAT I requires RVR or 550m or better, decision height of 200ft.
CAT II requires RVR of 300m or better, decision height of 100ft.
CAT IIIA requires RVR of 200m or better, decision height 50ft.
CAT IIIB requires RVR of 75m or better, no decision height.
CAT IIIC has not RVR or decision height, but is basically never used as the aircraft wouldn’t even be allowed to taxi once it had landed.
What are the three types of augmentation GNSS can use? How accurately are each of them (in terms of approach categories)?
Ground based, space based and aircraft based, called GBAS, SBAS and ABAS, respectively. GBAS is CAT III capable, SBAS is CAT I capable, and ABAS is non-precision.
How many satellites are required to have a reliable position without SBAS or GBAS? What is the name of the process which makes this possible?
Either 6, or 5 with another on-board altitude measuring system. This is possible because of RAIM - Receiver Autonomous Integrity Monitoring.
How is monopulse SSR able to resolve position from only 1 hit?
By measuring the incoming signal multiple times across the length of the antenna array, and then comparing the times between signal arrivals in order to discern the angle they arrived from.
How accurately do mode C and mode S report altitude?
To 200ft and 25ft, respectively.
What are the two types of response from a mode S transceiver? What data are shared between them?
Elementary and enhanced responses. Both will include the transponder address, the transponder’s report of its own capability, the flight status (airborne or on the ground), and the flight ID.
What is ADS-B, and how does it work?
ADS-B is a secondary surveillance tool. It stands for Automatic Dependent Surveillance - Broadcast, and it is basically the aircraft constantly shouting some details about its flight in all directions all of the time. It is sent as part of the mode S protocol, but functions whether or not mode S SSR is in use.
What is multi-lateral guidance, how does it work, and what is the name of the system which employs this principle?
Multi-lateral guidance is working out where something is by triangulating its position based on its ADS-B signals. It only really works in places like aerodromes, where multiple ADS-B masts are likely to be clustered together, where it is called MLGS - Multi-Lateral Guidance System. When combined with ground radar, it is called ASMGS - Advanced Surface Movement Guidance System.
