This lesson guide for instruction of students in grades 3-5 contains activities in mathematics, science, and technology. The NASA "Why?" Files is a series of instructional programs consisting of broadcast, print, and online elements. Emphasizing standards-based instruction, Problem-Based Learning, and science as inquiry, the series seeks to motivate students to become critical thinkers and active problem solvers. Each program supports the national mathematics, science, and technology standards and includes a 60-minute video broadcast, a companion educator's guide, Web-based activities and materials, and information about NASA programs, projects, facilities, and researchers. The materials in this lesson guide relate to aviation design. Included are the relationship of the material to national geography, science, mathematics, and educational technology standards; activities and worksheets; vocabulary lists; and guides to further resources. (MM)