
Photo credit: Daily Mail
Here are some rarely seen pictures show how engineers in 1960s California secretly developed the SR-71 Blackbird for the US Air Force, currently still the fastest unclassified aircraft. These rarely seen once classified photos reveal how Lockheed built three types of Blackbird – A, B and C in Burbank, California. All of the SR-71 models were built by American aerospace company Lockheed under a ‘black project’. The SR-71 Blackbird has held the world record for the fastest air-breathing manned aircraft with a record speed of 2,193.2mph, since July 28, 1976. To withstand the high temperatures generated by friction due to sustained Mach 3 flight in the upper atmosphere, the SR-71 required an array of specially developed materials including high temperature fuel, sealants, lubricants, wiring and other components. Click here to view the first image in today’s viral picture gallery. Continue reading to watch the five more popular viral videos of today.