MIT Chrysalis

The Chrysalis was a human-powered biplane, designed and built by graduates and undergraduates of the Massachusetts Institute of Technology, with Professor Eugene Larabee acting as Project Adviser.^[1] MIT had previously built two HPAs, the BURD and BURD II, both of which were unsuccessful.^[2]

Design work began in late 1978, with a 1/8th scale flying model being built to verify aspects of the design.^[3] The Chrysalis was a biplane of conventional configuration, fitted with a tractor propeller. The biplane's wire-braced wings were unstaggered, and the outboard panels of the lower wing were set with a 6° dihedral. The fuselage was of the pod-and-boom type. The aircraft had a primary structure of aluminum tubing, and a secondary structure made of styrofoam, balsa, and carbon fibre.^[1] The entire aircraft was covered in transparent Mylar film. The undercarriage had a single, castoring, monowheel.^[1] Lateral control was achieved by wing warping, with directional and pitch control being achieved by the all-flying tailfin and tailplane.^[1]

Construction of the aircraft took 91 days, and involved 20 people and 3,500 hours of work.^[2] It first flew on June 5, 1979, at Hanscom Field airport in Bedford, Massachusetts with designer Harold Youngren piloting the craft.^[3] Between then and its dismantling in September, the Chrysalis made a total of 345 flights, with 44 different pilots.^[1]

The Chrysalis was notable for being the first aircraft to use a 'minimum induced loss' propeller, the design of which was based on the work of Professor Eugene Larrabee.^[4] The MIT team also built the propeller used by the MacCready Gossamer Albatross.^[2]