In article Bruce Hoult writes:
On Mar 5, 8:44=A0am, John Smith wrote:
If you ever want to climb above 15,000 ft in an airspace where a
tansponder is mandatory (which I do regularly), then you are just plain
illegal with the TT21. This may be "fairly meaningless" for you, it's
not for me and should not be for any pilot.

Saying something is "illegal" is a fairly useless statement. A lot of
things are illegal, ranging from driving at 60 in a 55 zone and on up.

I think you need to explain:

- what is the likely safety implication of flying above 15000 with a
TT21?

I suspect the answer is "none whatsoever".


Unless, of course, the encoder actually cannot encode significantly above
that altitude.

Or, if it encodes incorrect values, resulting in that airliner hitting you
and going down with all aboard. That will look about as bad as not having
had a transponder in the first place.


- what is the penalty for being caught doing so? What is the chance of
being caught?

The first part probably depends on how you are caught.

Alan