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 .
First Armed Airplane. In 1912, a Wright Brothers plane, the first airplane armed with a machine gun was flown at an airport in College Park, Maryland. The airport had existed since 1909 when the Wright Brothers took their government-purchased airplane there to teach Army officers to fly.