The purpose of this thesis is to discuss the design, development and testing of a pneumatic telescopic wing using pneumatic actuators that permit a change in the aspect ratio while simultaneously supporting structural wing loads. The key element of the wing is a pressurized telescopic spar that can undergo large-scale spanwise changes while under loadings in excess of 15 lbs/ft2. The wing cross-section is maintained by NACA0013 rib sections; telescopic skin sections preserve the span wise airfoil geometry and ensure compact storage and deployment of the telescopic wing. Several iterations led to a full-scale telescopic wing assembly that was tested in the Glenn L. Martin Wind Tunnel at the University of Maryland. These tests included measurements of Lift, Drag, and Lift to Drag ratio at a variety of Reynolds numbers. The telescopic wing was tested in several configurations and experimental results were compared to finite wing theory results. Preliminary aerodynamic results are promising for the variable aspect ratio telescopic wing.