Dick, you said-
Ozbusdriver, what you are saying is that you would trust an unproven system that has not been certified yet - i.e. ADS-B ‘in’ - over a proven certified system, which (when Resolution Advisories are complied with) has never resulted in a midair collision in its history. I know which equipment I would be trusting, and that is the proven equipment.
Your TCAS is not certified for traffic INFORMATION. I will trust an uncertified ADS-B "IN" supplying traffic INFORMATION data to an uncertified PDA over using a TCAS for the same task. TCAS is the LAST line of defence. It matters not how accurate in azimuth(it cannot be used for this purpose) When your alarm goes off you follow the TCAS instructions immeadiately, do what the TCAS tells you to do to avoid the conflict. Climb or Dive
NO TURNS!
Look, TCAS software is brilliant considering the time it was invented, it has been improved by errors and incidents over the years to arrive at what you have now as part of your million dollar avionics suite. It just doesn't compete with radar or ADS-B simply because every bit of data TCAS uses is relative to your aircraft position, which is dynamic. TCAS calculates any threats within a certain parameter sphere around the entire aircraft. Its good enough to deduce 1200kts and 10000fpm vertical closures to give you
TIME to react to any threat. However, because it is relative it is easily tricked.
This is why you must never use TCAS for traffic separation maneuvers. You could just as easily turn yourself into your worst nightmare in seconds. Only radar and ...yes, you guessed it...ADS-B will give the actual vector information of your target. Without this information it is impossible to calculate whether you are safe or not. TCAS cannot tell where that aeroplane that is stationary in your windscreen that is actually going to collide with you is. It will tell you it is 45degrees to your side regardless of the actual position relative to you.
This is why I mentioned so many posts ago about ATC not necessarily being happy about a pilot second guessing and trying to arrange their own separation. TCAS does not have the information to allow a pilot to self separate. So, I say again, I will trust a non certified ADS-B "IN" any day over a TCAS to actually show me where the traffic is and where IT is going.
Stop trying to prop up your argument like you have been doing for the last gawd knows how many years. TCAS is not a traffic INFORMATION device.
Traffic
Collision
Avoidance System, there is nothing in there that says information.
EDIT- just to add, ask someone from Grumman about the problems they are having trying to use TCAS to give them some sort of traffic awareness to the Global Hawk. Once ADS-B is up their problems go away.