At the time, the continued wing failures were attributed to poor workmanship and materials at the Johannisthal factory. In fact, the cause of the wing failures lay in the sesquiplane arrangement taken from the Nieuport. While the lower wing had sufficient strength in static tests, it was subsequently determined that the main spar was located too far aft, causing the wing to twist under aerodynamic loads. Pilots were therefore advised not to perform steep or prolonged dives in the D.III. This design flaw persisted despite attempts to rectify the problem in the D.III and succeeding D.V.