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Old 16th Apr 2021, 12:18
  #50 (permalink)  
missy
 
Join Date: Mar 2000
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Originally Posted by UnderneathTheRadar
The objective is to consider the requirements to use airspace and all of the controls available - airspace type, procedures, technology (radar, ADSB receivers, ADSB-in, ADSB-out, TCAS, GPWS, EGPWS, CATI, CATIIIB) etc - and determine which combination provides 'about the same' residual risk as the next location. For practical reasons this is limited to a few different systems - generally we think of Oceanic, A, C, D, E & G in Oz but with special procedures in areas where an increase in procedure/cost to the next level up isn't justifiable but 'something' should be done - that's where an alternative airspace system may be used - CA/GRS or VFR LOEs.
UTR, some of these are safety nets - GPWS, EGPWS, TCAS and shouldn't be used to determine available controls.

In the case of TCAS - "TCAS does not substitute for air traffic control, but acts as a defence against a breakdown of the air traffic control system". "Australian aircraft that is a turbine-powered commercial aeroplane must not, except in certain limited circumstances, begin a flight unless it is fitted with an approved TCAS II that is serviceable".

The ATS Flight Notification doesn't have any reference to TCAS, there is no abbreviation for TCAS, there is no reference on an ATC display to indicate that an aircraft has or doesn't have TCAS, there is no reference on an ATC paper flight progress strip (most Towers) that the aircraft has or doesn't have TCAS, there are no procedures in MATS to indicate what an ATC should do if a pilot advises that TCAS is inoperable. TCAS is a pilot safety net and as indicated above, acts as a defence against a breakdown of the air traffic control system.

Same for GPWS, EGPWS etc.

Same for MSAW (Minimum Safe Altitude Warning), an ATC Safety Net for defined portions of airspace for defined flight procedures (IFR).

Same for CLAM (Cleared Level Adherence Monitoring), an ATC Safety Net based on defined parameters.

Same for STCA (Short Term Conflict Alert), an ATC Safety Net based on defined parameters. The fact that there are numerous (100's daily) false alerts has meant that "true alerts are not responded to and all alerts are delayed in their response."
False alerts

Technology is important however Safety Nets have been developed for when the human has failed.
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