On Monday, June 4, 2018 at 7:07:57 PM UTC-7, Charles Longley wrote:
Did you not read my post? I said I sent a 337 in per the FAA’s guidance. I disagree with you that it was a “notification” 337. But everyone is entitled to their opinion.

I read your post, very carefully, and its not clear what you have done. Did you send a 337 to Oklahoma or the FSDO? Did you treat the installation was a major modification, and if so would you mind explaining why? Did you get the FSDO to approve Block 3 before sending it to Oklahoma? Did Oklahoma send you back the 337 with Block 3 approved? I appreciate your help here explaining exactly what you did, I suspect we may be talking at crossed purposes.

I again want to reiterate that ADS-B Out installations in gliders (I know you did a towplane) should normally be minor modifications, and therefore do not need major modification approval, but do require a "notification only" 337 filed with FAA HQ.