On Jun 16, 10:32*am, lanebush wrote:
If it is no longer in the configuration as described in the type
certificate plus any STC 's and/or field approved modifications. *So,
if your winglets are not approved via an STC or field approval (337
form) and are not listed in the type certificate then you are not
flying under a valid airwothiness certificate. *There is the question
of major/minor *modification/repair but I believe winglets would not
pass the test of being excluded from the "major" catagory.

True there are lots of STCs about winglets.