18. Arthur M. Young, American inventor, started work on model helicopters in 1928 using converted electric hover motors to drive the rotor head. Young invented the stabilizer bar and patented it shortly after. A mutual friend introduced Young to Lawrence Dale, who once seeing his work asked him to join the Bell Aircraft company. When Young arrived at Bell he signed his patent over and began work on the helicopter. His budget was US$250,000 to build 2 working helicopters. In just 6 months they completed the first Bell Model 1, which spawned the Bell 30, later succeeded by the Bell 47.