although nominally a development of his earlier dfs rhönsperber, hans jacobs' sperber senior was a completely new design intended to improve on the performance of its predecessor and to accommodate larger pilots. it was a shoulder wing aircraft with a double straight tapered gull wing, built around two spars and fabric covered apart from the leading edge from the front spar forward and the wing roots, which were plywood skinned. the wing roots were carefully faired into the fuselage. the inner panels, filling about one third of the span had only slight taper, the sweep entirely on the trailing edge, and about 10° of dihedral. outboard the taper was much stronger, with a taper ratio of 0.45. here the leading edge was slightly swept but there was no dihedral. ailerons occupied the whole of the outer panels' trailing edges.