Originally Posted by
USMCFLYR
One time I flew down the Hudson River and noticed NUMEROUS aircraft (helos) flying around the Statue of Liberty and I lost count of the number of GA aircraft flying down either side of the Hudson. What would be the limits of the TCAS resolution and how wuld so many aircraft opearting in close proximity be displayed and how would the pilot make out the information? I could see a pilot get overwhelmed with the amount of information given to him and be head's down in the cockpit looking at the plethora of information instead of looking outside where he SHOULD be especially when operating in a high traffic area. The Mark 1 Mod 0 eyeball (and the brain it is attached too) is (are together) the number one sensor - all other sensors are TOOLS to help out and improve SA.
USMCFLYR
Current TCAS is pretty useless in a high-density traffic environment. The mode-C based system simply does not have the bearing and range resolution to deal with multiple close-in contacts. You just get a screen full of targets clustered around the center...if you get an RA in that situation, the guidance would probably put you into another conflict.
That's why RA's are disabled at low altitude, due to high traffic density on and around airports.
A future system based on ADS-B Out could provide better resolution based on more precise positional data.