On May 15, 10:54 am, Mike125 wrote:
Its curious to me that there is an excemption while within the
(presumeably) more crowded airspace but not while above it.

Mike

There is NO exception within Class B or C airspace, by regulation you
must have a transponder operating. The only exceptions are the 30 nm
"Mode C veil" defined by 91.215(b)(3) and above 10,000 feet MSL.

Todd