1 Discard any hammer with mushroomed or chipped face or with cracks in the claw or eye sections. 2  Wear safety glasses or goggles, or a face shield (with safety glasses or goggles).  Strike a hammer blow squarely with the striking face parallel to the surface being struck.
The first jet airplane was the Heinkel He 178 made in Germany in 1939, right before the outbreak of World War II .
Origins of the Name. The very first piloted helicopter was invented by Paul Cornu in 1907, however, this design was not successful. French inventor, Etienne Oehmichen built and flew a helicopter one kilometer in 1924.Another early helicopter that flew for a decent distance was the German Focke-Wulf Fw 61, invented by an unknown inventor.gor Sikorsky's helicopters had the control to fly safely forwards and backwards, up and down, and sideways. In 1958, Igor Sikorsky's rotorcraft company made the world's first helicopter that had a boat hull and could land and takeoff from water.