I have a Form One for both my radio and transponder.

/Robert

John Smith skrev:
jcarlyle wrote:

First, it appears to this US pilot that one of the uses of a Form One
is to certify that a new part is airworthy, with the basis for
airworthiness being that the part was made in accordance with a TSO or
some other approved technical specification. Is this correct?

Roughly said, yes. EASA Form 1 ist the exact equivalent of the FAA Form
8130–3, it even has the same blocks. (And EASA honors FAA 8130-3 forms.)

Second, why would a plane made in Europe not have a Form One for all
installed equipment?

Form 1 (or an equivalent certificate) is only required for required
equipment.

I'm not sure how transponders, radios and ELTs are handled because they
are not required but must be approved somehow.