On 14/12/2017 07:50, Andreas Maurer wrote:
....
Several causes:
- mainly wing tip clearance: The wing tips are far behind the landing
gear and dihedral is only 2 degrees, they come down when the nose goes
up, creating ground clearance problems

Same reason as the dihedral on 707/DC-8, etc tailplanes I understand

- with the wing out of the way lots of space for a really strong nose
gear (one of the famous weak points of the SB-13)

- the wing spar is now over the knees of the pilot, leaving plenty of
easily accessible space for the controls, mixer and Haenle-type stick
between wing spar and instrument panel

Spar OVER the pilot's knees?? Sounds like emergency exits might be
interesting - and not very rapid.

- lots of space for the pilot (I'm 6'7" and fitedt comfortably in the
prototype fuselage on the Aro aviation fair)

In their own (German) words:
https://akaflieg-karlsruhe.de/ak-x/aerodynamik/

--
GC