"My 10 year old son bought this and excitedly built the first helicopter. Couldn't get it to fly and neither can I after considerable effort. The helicopters are cheap tat and the whole thing is a massive disappointment. Having been building Lego for decades, I never thought I would say this about any of their products, but this one is complete rubbish. Surprised it ever got past first base of product testing. Item returned for refund."