Tandem Wing Model on Testing Mounts (1927)

A rear view of a dark tandem wing aircraft model mounted on three metal pegs for wind tunnel testing. — Tandem Wing Model on Testing Mounts (1927) · Donald A. Hall Estate Collection

Preparing for rigorous aerodynamic evaluation, Donald A. Hall Sr. mounted this tandem wing model on metal standoffs. This 1927 archival image illustrates the exacting scientific methods he used to prove the stability and lift of his revolutionary twin-wing designs.