The Blackbird takes flight from Edwards Air Force Base

The Blackbird takes flight from Edwards Air Force Base How they built the Blackbird: Fascinating pictures show birth of Lockheed's top secret SR-71 spy plane - which is STILL the fastest plane ever built after 39 years Lockheed SR-71 Blackbird was built in the 1960s by engineers in California Long-range strategic reconnaissance aircraft was made for US Air Force Classified pictures reveal how Lockheed built A, B and C versions of plane Held world record for the fastest air-breathing manned aircraft since 1976 By Keiligh Baker for MailOnline Published: 17:17, 9 February 2015 | Updated: 07:12, 10 February 2015 2.7k shares 309 View comments These fascinating pictures show how engineers in 1960s California secretly developed the SR-71 Blackbird for the US Air Force – a plane which still holds the record for being the fastest ever aircraft. The Lockheed SR-71 Blackbird is a long-range, strategic reconnaissance aircraft and these once classified photos reveal how Lockheed built three types of Blackbird - A, B and C in top secret conditions in Burbank, California. The aircraft were built by American aerospace company Lockheed under a 'black project' - a highly classified military defence project unacknowledged by the government until its declassification. Since July 28 1976 the SR-71 Blackbird has held the world record for the fastest air-breathing manned aircraft with a record speed of 2,193.2mph. Scroll down for video Scientists at Lockheed's Skunk Works in Burbank developed the plane -this picture shows their assembly line +11 Scientists at Lockheed's Skunk Works in Burbank developed the plane -this picture shows their assembly line Lockheed engineers working on the Blackbird - the dark colour acts as a camouflage +11 Lockheed engineers working on the Blackbird - the dark colour acts as a camouflage To withstand high temperatures during sustained Mach 3 flight, the Blackbird required an array of specially developed materials including high temperature fuel, sealants, lubricants, wiring and other components +11 To withstand high temperatures during sustained Mach 3 flight, the Blackbird required an array of specially developed materials including high temperature fuel, sealants, lubricants, wiring and other components Renowned American aerospace engineer Clarence 'Kelly' Johnson was responsible for many of the design's innovative concepts. During reconnaissance missions, the SR-71 operated at high speeds and altitudes to allow it to outrace threats - if a surface-to-air missile launch was detected, the standard evasive action was simply to accelerate and out fly the missile. RELATED ARTICLES Previous 1 2 Next Dry Roasted Peanuts on a White Background. Image shot 2011. Exact date unknown. 'Fasten your seatbelts and put away your peanuts': Call for... Baby born prematurely in New York leaving parents facing a... Pair of skydivers narrowly escape getting shredded in half... Share this article Share The SR-71 was designed to have basic stealthy characteristics and served as a precursor to modern stealth aircraft. The Blackbird served with the U.S. Air Force from 1964 to 1998 and a total of 32 aircraft were built; 12 were lost in accidents, but none were ever lost to enemy action. Around 93% of the plane's frame was made of titanium alloy which allowed the aircraft to fly fast and high +11 Around 93% of the plane's frame was made of titanium alloy which allowed the aircraft to fly fast and high An SR-71B trainer over the Sierra Nevada Mountains in 1994 - the raised second cockpit is for the instructor +11 An SR-71B trainer over the Sierra Nevada Mountains in 1994 - the raised second cockpit is for the instructor Since 1976 the Blackbird has held the world record for the fastest air-breathing manned aircraft +11 Since 1976 the Blackbird has held the world record for the fastest air-breathing manned aircraft The Blackbird takes flight from Edwards Air Force Base Flying at 80,000 ft meant that crews could not use standard masks, which would not provide enough oxygen above 43,000 ft, so specialist protective pressurised suits were made. The plane's titanium skin was capable of surviving temperatures up to 482C. The SR-71 was the world's fastest and highest-flying operational manned aircraft throughout its career and is believed to be the most advanced airplane ever built in relation to the technology available at the time.