Alain,
https://www.avweb.com/features/avweb...s-perch-index/
This man wrote many articles. Some will pertain to your question.
He has history with the GAMI people, so he knows what he wrote about.
I suggest article 31-36 first... then highly recommend the rest of his stuff.
John passed away 2 years ago..
We lost a great man, and a friend to aviation.