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SIGNAL REFLECTIONS
Transponder signals can be reflected by nearby structures.
This can result in unreliable altitude and iNM indications,
especially near hangars or buildings. This condition occurs
primarily when the host aircraft is on the ground, since the
top mounted TCAD antenna is less exposed to reflections
while in flight.
OVERLAPPED REPLIES
When two aircraft are interrogated at the same instant, the
replies received by TCAD can be mixed, degrading the
ability to decode the replies. This is more likely to occur in
higher density areas, when both aircraft are illuminated at
the same moment by the same radar.
By using degarbling techniques, the processor can often
provide data on the closest threat. In some instances, both
aircraft will be decoded, and in other instances, accurate
decoding is impossible. This means the traffic may not be
displayed on TCAD at all. By keeping the shield size small
in high-density areas, the potential for garbled replies is
minimized.
CAUTION: Federal Regulations state that "When an ATC
clearance has been obtained, no pilot in command may
deviate from that clearance, except in an emergency, unless
he obtains an amended clearance." Traffic information
provided by the Ryan TCAD does NOT relieve the pilot in
command of this responsibility.
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