The airplane known in America as the JL-6 is the T-13 of Prof. Hugo Junker. The airplane is constructed entirely of metal, chiefly duralumin, and contains several unique structural features. The most important features are the multispar wing bracing and the monococque type of fuselage. Both of these types of construction are extremely difficult to design rationally, as they are very indeterminate statically. Fortunately, the Air Service has been able to obtain blue prints of some of the stress analysis used in the design of this airplane. This document summarizes this data.