THE XL FUSELAGE WIDTH

The XL fuselage width provides 5 cm more space in the pilot arms area. Because of different shape of upper longeron is fuselage wider in the instrument panel area also.  There is more space for legs too.

Difference between the STD and XL width.

THE XL FUSELAGE WIDTH
XL width version
THE XL FUSELAGE WIDTH
Standard version
THE XL FUSELAGE WIDTH
Drawing SD-1B XL width fuselage