I did not use a pipe, but a projected curve.
I agree, that area needs to be better, it’s one of the reasons I didn’t post the geometry 
These type of solutions often need a couple of iterations to get it right, I just wanted to illustrate the modeling approach.
Nothing Fancy. Just connected the blue with one fillet and then a closed loop of fillets to connect the blue to the tan.
This is not the only fillet solution. There are at least 2 more possible depending on which fillets are done first and which cross over that.
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… which would be a great field for new tools.
I learned the pipe-trim-tricky 20 years ago in the university. - it s nice for tangent continuity - but not for G2, especially if the 2 surfaces have different curvature or curvature-direction
I always hoped to have nicer tools that helps to find good trimming positions.
It’s a technique I learned from this book back in the day I am sure you are familiar
Kyle touches on that subject aswell around 1:05:00
Like I posted to gijs I learned it from the AK3D- car modelling with rhinoceros book when you say 20 years it probably had its origin way back then
I like to use it when fillets don’t produce satisfying results even today with Rhino 8 does the job visually
Hello, I Know I’m late to the party, but this is my (partial) solution.
It’s probably overcostructed but I think it shows how much you can be creative in solving this round in multiple ways.
And this the Zebra:
It tooks my a bit time than planned but I’m satisfied of the result.
Just for comparison
I’ve collected all the solutions and made a similar one to Gijs (3rd) and one clsoe to JCarrutere (4th) in this file:
BlendSrf_collection.3dm (3.0 MB)
Thank to everyone, this “challenges” are very istructive.
I can see how the partial part can definitely work to so many ways to this challenge 
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well, fillets are sometimes really not easy, since i have no experience with other CAD with this subject and i personally also rarely have to fillet too often thankfuly which seems a nightmare at times without the proper expertise, and even though i am not a fan of advocating SubD it still seems to be interesting what results it can produce, specifically in that it presents you with a more body homogenous surface continuity, which may not be always what is wanted for sure but i can not ignore it either.
if you give it a good go you might be able to use it for production? i mean its the endresult that counts if its usable, not how cool we can be 
ok that sounds dumb.
one thing i love in Rhino since V8 is that we have not only Quadremesh (v7), but also Shrinkwrap now, those 2 in combinations are a real bliss to work with.
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Solidworks is pretty good at fillets you should try parametric cad one day its quite nice
Check this one:
This is so much better explained thanks
Since its older than the book it shall be known as the “James carothers pipe trim trick” for now (sorry if I butchered the last name)
Wonder what other ancient methods exist out there 
I believe that the pipe cutting method followed by a blend surface was first explained in Rhino 2’s help files. The two files I remember were a yellow duck and some green creature (maybe a frog?). The same files were included in some newer Rhino versions as well.
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