"**THE-RFI-EMI-GUY**" wrote in message
...
question for the group.

In the case of the Legacy vs GOL, with the closing speeds of those two
planes
and given the range of TCAS, exactly how much warning would the pilots have
had if TCAS had been working?

The RA warning is issued based on time (about 30 sec). In a head-on
encounter at 0.8M, that would be 8 to 10 nm.

TCAS range is not a fixed number as it is affected by many factors, but 30
nm minimum is a realistic number under almost all conditions. That would be
1 minute or more before the RA would be issued. It takes TCAS about 5 to 7
sec to build an initial track file on a target. That track file is used to
perform the prediction. So the system had lots of time to work.

TCAS was designed in the '80s when the Concordes were flying. One basic
design requirement was that it had to work on two Concordes closing head on
at Mach 2.

Gerry