This paper discusses the design of a fixed-wing UAV to carry a 8 kg electro-optic payload for 6 hrs to operate at a maximum altitude of 3 km. H-tail, twin-boom, pusher configuration with fixed landing gear is chosen to ensure unhindered payload operation. A hybrid air-frame with composite (CFRP) lifting surfaces and a metal (Al6061-T6) fuselage with 3D printed nose cone was designed and fabricated to ensure manufacturability. Composites are preferable for the lifting surfaces as they are subjected to unequal loads in different directions and the material can be tailored to reduce weight. For the fuselage, composites offer no such advantage since there is no necessity for directional strength. Its fabrication with metals having well established manufacturing processes leads to a reduction in cost. Though structural weight optimization of the lifting surfaces has not been completed in this design, hybrid structure was fabricated to understand the difficulties in manufacturing/ assembly of the composite lifting surfaces with a metal fuselage. The detailed design, fabrication and assembly of the air-frame are discussed. © 2019, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.