Andy,

Maybe I can help.

Winter uses two different nomenclatures. The 4 FGH 40 altimeter is
also known as the 4555 (download the Winter Bordgerate catalog, and
you'll see). You can see on the Products page that the 4555 has an
EASA Form One. Here's the tricky bit - I have the older JAA Form One,
and on it under remarks it says the 4555 has TS 10.220/48, which is
equivalent to TSO C10b.

For what it's worth, I have a transponder and the shop was happy with
my 4 FGH 40 during the data equivalence checks.

-John


On Dec 7, 1:40 pm, Andy wrote:
2. Substantiation that the Winter 4FGH40 is TSO compliant.

As the owner of an 4FGH40 who is considering installing a transponder
this winter I look forward to that information with interest.