Many transponders in close proximity

jettester wrote:
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#4. MODE S transponders have a discrete ID code embedded in the
transponder that is supposed to be set to your aircraft registry ID
(look on the FAA website for your aircraft registry information and you
will find that ID for your aircraft). Mode S talks to other mode S
equipped transponders, and is typically used to provide TCAS (Traffic
Collision Avoidance System) information to issue the advisories to each
aircraft. If you have this feature, and were to pullup rapidly with
another mode S aircraft overhead, it could set off his traffic warning
system.

A mode S transponder is not required for an aircraft to be detected
by TCAS. The conflicting traffic only needs mode C for the TCAS
to give an RA. The only advantage mode S gives is that if you have
TWO TCAS equipped aircraft, they use the mode S datalink to coordinate
a resolution (one climbs the other descends).