SR-71 Titanium
The SR-71 was engineered by Lockheed and the Skunk Works division to be a long-range reconnaissance jet capable of flying at an altitude of 85,000 feet. Because of it's tremendous speed (Mach 3.2+ or 2,464 MPH), not a single SR-71 was shot down during service. This high speed also required that the aircraft be constructed with a special titanium alloy.