BIRD BAIT: A penny-weight model A recently built scale model shows how small a viable remotely controlled aircraft can be.  Matthew T. Keennon, program manager at AeroVironment, made a 4.4 in. wingspan model of SE5 biplane weighing only 2.5 gm (less than 1/10th ounce) about the weight of a penny. The wings are a single sheed of 0.015 balsa wood steamed to an undercamber.  It has a very thin leading edge similar to butterfly and dragonfly wings. "Muscle wire" actuator and tiny high-performance battery are key to the small size.  Motor, gearbox and prop weight only 0.6 gm.  The aircraft has flown 4 minutes at a time.

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