Helicopter is a fun but complex sign. Make a horizontal number 3 sign with your non-dominant hand, with palm facing your body, and thumb sticking up. Then cover it with your open, dominant hand creating a movement that mimics blades. Wiggle your 'blades' hand as both hands move in small flying motions in front of your body.
We use the sign for helicopter to expand our baby's vocabulary in association with transport. If you are fortunate enough to live in close proximity to a small airport,consider taking your baby to watch helicopters land and take off.
Both boys and girls show great interest for aerial transport. Teach helicopter by visiting your local municipal airport or by purchasing a helicopter toy.