This book recounts the experiences of three very talented parachutist brothers, inventors and engineers named Nikolay, Vladimir and Anatoly Doronin.

Their creative nature made a great contribution to the USSR's skydiving development and increased airdrops' safety, earning the pilots and skydivers appreciation and respect thanks to their inventions' reliability.

Despite their youth, in 1938 they invented the PPD-1, the World's first Parachute Automatic Activation Device (AAD) designed to open a parachute, housed inside a small grey box, causing a revolution in the Skydiving Community.

During the Second World War years, the Doronins developed seven new types of AAD devices, plus an universal suspension for airdropping bulky loads, and some thirty inventions that saved the lives of thousands of paratroopers, pilots, and aviation athletes.

Their creations are still used today in Cosmonautics, Aeronautics, military and sports parachuting.