Earlier, (Paul Lee) wrote:

Is 337 required in a new kit project?
It is for "Major repairs and alterations".

The way I understand it, form 337 records a deviation between a
particular aircraft or subassembly and its type certification data.
Homebuilts, by and large (there are exceptions), do not hold type
certification, so form 337 is neither required nor valid for them.

If anybody wants to hijack this thread, all they have to do is name a
series of homebuilt kit aircraft that generally carry standard
airworthiness certificates. I know of one...

Thanks, and best regards

Bob K.
http://www.hpaircraft.com