"Paul kgyy" wrote in message
ups.com...
If empennage elimination is such an "obvious" improvement, how come
it's taking so long?

It didn't take long at all. Read up on Jack Northrop

I'm guessing that controllability is the major problem, and developers
are trying to fix that with electronic control systems?

Jack Northrop had it figured out and working extremely well back in the
'40s.