For more than four decades now the SR-71 Blackbird has been the object of noble admiration, lofty praise, and a great deal of conjecture. Conceived and created in an era steeped in cold war secrecy, the Blackbird has been veiled in mystery and inscrutability from its first flight in 1964, right up to its last flight in 1999. Generations of pilots and wannabe pilots have drooled over hazy snapshots of the plane that everyone knew existed, but few ever chanced to spot. Now in retirement, the most spectacular aircraft ever built, at last is accessible to those infatuated with the plane that spawned a whole new generation of stealth aircraft and technological advances across the entire aviation landscape.
With a cruising speed of Mach 3.2, or about 3,500 km/h, at a height of 85,000 feet, the SR-71 Blackbird remains the fastest and highest flying air-breathing jet aircraft in the world. The only aircraft to come close to the Blackbird's astonishing speed is the Russian MiG-25 Foxbat, a fighter plane that can attain speeds of over Mach 3, but only for a few minutes at a time. The Anglo-French Concorde is the only aircraft besides the Blackbird that can fly at supersonic speeds for hours at a time, although not nearly as fast as the Blackbird.
Over the last forty years the SR-71 Blackbird has accumulated many outstanding achievements, and to date the aircraft holds all of the official airspeed and altitude records. In September 1974, the Blackbird set a speed record from London to Los Angeles, travelling at an average speed of 2,309 km/h. A week later the Blackbird travelled from New York to London in a record time of 1 hour, 54 minutes, and 56.4 seconds! In July 1976, a Blackbird set both an 'Altitude in Horizontal Flight' record at 85,069 feet, and a 'Speed Over a Straight Course' record of 3,529 km/h. A few days later the same Blackbird set a 'Speed Over a Closed Circuit' record of 3,366 km/h.
The Blackbird is a large aircraft that compares in size to a Boeing 727. Manufactured from a titanium composite, the unique airframe is designed to withstand the heat generated from the friction of flying at Mach 3. The landing gear is the largest piece of titanium ever forged in the world. At the time the United States did not have enough titanium to build the fleet and, ironically, bought the needed titanium from Russia. Even the main gear tires are impregnated with aluminium and filled with nitrogen to deal with the extreme heat at cruising speed. The component parts of the Blackbird fit very loosely together to allow for expansion at high temperatures generated at cruising speed. Since the tanks in the fuselage and wings only seal at operating temperatures, fuel leaks out constantly while the aircraft is at rest on the ground. There is little danger of fire since the JP-7 fuel used in the Blackbird is very stable with an extremely high flash point.
In order for the Blackbird to fly worldwide missions, this fuel-thirsty bird has its own dedicated fleet of modified KC-135Q tankers for refuelling in mid-air. The Blackbird takes off with a very light fuel load, rendezvous with a KC-135Q tanker seven minutes after take off, and then accelerates to cruising speed and operational altitude, which is about Mach 3.2 at 85,000 feet. After refuelling, the plane can fly up to 6,000 km without refuelling. Upon completion of its mission, the Blackbird has another rendezvous with a KC-135Q tanker before returning to base.
The Blackbird is a highly sophisticated aircraft, requiring equally sophisticated pre-flight procedures. The crew members wear space suits identical to those worn by the crews on the space shuttle, and just like the space shuttle crew they have to breathe in pure oxygen and filter out any other gas from their bodies before takeoff. After the engines are started, TEB is shot into the tailpipe of the aircraft, producing a spectacular green flash from the ejector. After about 25 minutes of pre-flight checks, the pilot moves the airplane onto the runway, where he performs a series of engine run-ups before the ground crew pull the chocks. Starting with a slow roll down the runway, the Blackbird thunders into rapid acceleration when the afterburners are lit, and then accelerates to approximately 440 km/h before graciously lifting off. One Blackbird pilot has compared the physical sensation of taking off in a Blackbird to that of being strapped to a supersonic freight train moving downhill!
The Blackbird is fitted with two J58 engines, each producing 32,500 pounds of thrust – enough to drive the largest ocean liners. They are the largest of their kind and still remain the most powerful in the world. The J58 engines are unique in that they function as normal turbojets at subsonic speeds, and as ramjets at supersonic speeds.
The United States Air Force developed the SR-71 Blackbird as an unarmed global strategic reconnaissance aircraft during the height of the cold war before the advent of spy satellites, primarily for reconnaissance missions over the former Soviet Union. Capable of flying at speeds and heights that made the aircraft impervious to the most sophisticated anti-aircraft defence systems in the world, not one Blackbird was ever shot down by enemy missiles, even though more than 1,000 missiles have been launched against it. The Blackbird never carried any form of armament, and the only things ever shot from the Blackbird were millions of photos.
The first SR-71 mock-up was reviewed on 13 June 1962. A month later, the J58 turbojet – the monster jet engine used in the Blackbird – completed its pre-flight testing, and in late 1962 the US Air Force commissioned Lockheed to build six SR-71 Blackbird aircraft – the first of a total of a total order of 50 SR-71 Blackbirds.
The SR-71 Blackbird made its maiden flight on 22 December 1964. Although the US President made public the existence of the Blackbird even before its first flight, the aircraft kept a Top Secret classification until its retirement in 2002. Although the US Air Force leaked information about the Blackbird's phenomenal achievements, it steadfastly refused to release any official photos until 1989, when the SR-71 program was officially terminated due to budgetary constraints. However, the retirement of the SR-71 Blackbird proved to be premature, and in September 1994, the US Congress voted to allocate 100 million dollars for the reactivation of three SR-71 Blackbirds.
In late 1999, the entire SR-71 fleet were put in flyable storage, where they remained until 2002, from where they were finally decommissioned and sent to museums across the US. The last SR-71 Blackbird flight was made at an air show at the Edwards Air Force Base on Saturday 9 October 1999.
However, like the mythological Phoenix bird that rises from its own ashes, the Blackbird once again seems to be ready to rise from its ashes. NASA's Revolutionary Concepts (REVCON) project is now considering the SR-71 as a future testbed for their Pulse Detonation Engine, a revolutionary approach for future high-speed jet propulsion. The engine will have no moving parts, yet greater propulsion efficiency, resulting in lower maintenance and direct operating costs. A proposal from NASA to fly the Pulse Detonation Engine captive carry atop the rear section of the Blackbird is currently under review.
Whether the Blackbird remains in retirement or not, this phenomenal aircraft will continue to soar in the memory of humankind as an unparalleled accomplishment in our first century of flight.