Ron Natalie wrote:
"Thomas Borchert" wrote in message ...

Ron,


Each aircraft registration has a mode S. It's
constant whether the N number changes


What's the difference between N number and aircraft registration in
the above quote?


You can change the N number. The Mode S is tied to the aircraft itself (the
model and serial #).

So the Mode S number bound to the airframe. Is that the Airworthiness
Certificate? It's all sort of strange because you can replace your
transponder, a wing, radios, fuel tanks, the engine... just what is the
"aircraft"? One view is that it is the file card-size plate that
identifies the aircraft. But I thought that has the N-number on it.

Let me guess: the aircraft is the same as the N-number and that cannot
be changed. The Mode-S number is simply a reflection of the N-number.
Removing the transponder from a plane probably requires the technician
to zero the Mode-S number in the transponder. Installing a transponder
requires the tech to lookup the Mode-S number based on the N-number