[Rashputin]

I'm sure they look at what works, but, there's also the fact that design thought in aerodynamics seems to come in waves with everyone reaching similar configurations based on the latest advances in what works with what's possible. If they see something already working no doubt they avoid a lot of what they may have tried otherwise and the similarity increases.

Sorta like at one time everyone had planes similar to the the Bee Gee, then poof, that was gone and if you mention it around younger folks they say, "The band ? Don't you mean BeeGees? They had an airplane?"

Then again, if you can get the design work someone else has done already and start with that, sure, why start from scratch and try things that have been tried and rejected for good reasons? Lenin knew where to buy rope, everyone on the planet also knows how to get blueprints and research data, so it's really just another black market to a much greater extent than people think.

[Bobalu]

[Oztrich Boy]

Pretty much going on for a century

At the end of 1916, the German Albatros dominated the skies above Europe, until the Brits introduced a new Sowpwith design

which then went Ancient Mariner on th e Albatros

The German response?