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The A-12 Archangel: Faster, Lighter, Higher than the SR-71

X Æ A-12

If like the rest of the world, you were wondering why Elon Musk and his girlfriend Grimes named their newborn son with the frankly bizarre name X Æ A-12 – then you’ve come to the right place. And yes, this does link in with our Megaproject today. The X stands for the unknown variable, Æ is the elven spelling for AI – but it is the A-12 that is of particular interest to us. 

Some might suggest it’s a little strange to name a child after a high-altitude reconnaissance aircraft which first flew in the 1960’s – but hey, I think it’s fair to say Elon Musk has been consistently thinking outside the box for a while now. 

Ok, enough with the baby names, let’s get down to business. The Lockheed A-12 came with the exalted nickname, ‘archangel’. For those of you who are a little biblically rusty, an archangel is an angel of high rank – a top dog if you will. And the Lockheed A-12 was exactly that. A thunderous Mach 3+ reconnaissance aircraft, which only served the CIA for 5 years, from 1963 to 1968 – and was only officially declassified in the 1990s. It was a phantom during its time in the skies, and because of its more famous younger sibling – the SR-71 Blackbird – it is an aircraft that has sadly slipped out of the limelight. Until today that is. 


A-12s in storage at Palmdale

You may have seen on Megaprojects we did a video on the U-2 aircraft, the American spy plane that was famously shot down over the Soviet Union in 1960. The U-2 had proven itself more than capable, but also much more trackable by radar than the Americans had initially thought. 

Despite much tinkering, known as ‘Project Rainbow’, the United States was not able to find a way to reduce the radar cross-section of the U-2, which would have made it much harder to track. So if you can’t improve the old aircraft, what do you do? Build an entirely new one of course. 

The American military often reaped the benefit of good old fashioned competition, and it was through one such battle of aviation minds that the A-12 emerged. Convair and Lockheed were both given the task of developing plans for a new high-altitude reconnaissance aircraft that would be able to supersede the U-2. 

The Convair model was known as Kingfish, while the first Lockheed plan was known as Archangel 1 – A-1 for short. If we fast forward slightly through the development, the crunch moment came as the Kingfish faced off against the Lockheed model, now known as Archangel 11. It seemed as if Convair were about to pinch a lucrative contract, but in the final stages, a few tweaks to the A-11 meant that it moved ahead of the Kingfish, and on the 26th January 1960, the CIA placed an order for 12 aircraft – now with the final name – A-12. The production project took the name, Oxcart, which when you consider the A-12’s blistering speed is wonderfully ironic. 


The construction of this aircraft well ahead of its time begins with a wonderful tale of Cold War business espionage. 

Today, titanium is widely used around the world in a variety of products, from space shuttles to tennis rackets, but its use in the late 1950s was still in its relative infancy. The U.S government typically received the titanium it needed from Titanium Metals Corporation, a U.S based company. However, its stockpile of this chemical element was severely limited and was completely insufficient for the A-12’s design requirements.   

There was one country with plenty of titanium in reserve, and indeed one that pioneered its use with military hardware – and I’ll give you yf-12-aircraft-model-in-the-10×10-foot-wind-tunnel-c06018just the one guess. The Soviet Union of course. Of all countries, the U.S needed to try and procure this precious alloy from its most fearsome enemy.

As you can imagine, it was completely out of the question for the Director of the CIA to pick up the phone and place an order with Moscow, so instead, they set up an elaborate scheme to purchase titanium from the Soviets using various back-alley sources, third parties and dummy corporations. Resulting in perhaps one of the most ironic ventures of the whole Cold War, that a plane that was being built to spy on the Soviet Union was partly from the Soviet Union – there is something wonderfully Manchurian Candidate about that. 

Just one more point about the titanium. At the time it was mainly used for small parts, but the design for the A-12 called for most of it to be constructed using the rigid, and difficult to machine, alloy. The aircraft’s curved layout, therefore, proved to be a dilemma to its designer and builders. A solution was found to cut small “fillets” of the material then to glue it to the underlying framework, rather than attempt to cut large scale pieces of titanium. As the design progressed further, these fillets were eventually replaced with strips of iron ferrite and silicon laminate which proved excellent at reflecting radar.    


A-12 60-6925, No. 122, mounted inverted for radar testing at Area 51
A-12 60-6925, No. 122, mounted inverted for radar testing at Area 51

As you might expect from such a forward-thinking aircraft, testing was rocky.     

The A-12 took to the skies for its first test flight on 26th April 1962, with test pilot Louis Schalk at the controls. The site chosen was Groom Lake, a salt flat located in the north of Area 51, and it was from this secretive location that a total of 2,850 test flights of the A-12 were carried out.

Its maiden voyage was an almighty 3 km (2 miles) at an altitude of just 6 metres (20ft) over the salt below. Despite some serious wobbling caused by the improper hook-up of some navigational chords, the flight was considered a success. 

The following day the A-12 left the salt flats once again, this time clocking up a total of 40 minutes in the air. Again, it was considered a successful flight, but it did begin to shed its titanium fillets as it climbed above 90 metres (300 ft). I guess the term success can be a fairly loose concept. Engineers spent four days searching the area for the missing fillets – well you probably would too if you’d gone to all that trouble of fooling the Soviets into selling the titanium. Losing them was clearly not an option. 

In 1963 the program lost their first A-12 – as the aircraft with the distinction “Article 123” crashed near Wendover in Utah. Though the pilot successfully ejected, this did pose a problem of what exactly do you say when a top-secret spy plane crashes on American soil. 

Kenneth S. Collins, the pilot of the plane that had gone, was dressed in a standard flight suit which probably helped with the cover story that a Republic F-105 Thunderchief, a fighter bomber that had been operating for the past five years, had crashed nearby. I suppose it would have been a little awkward if he’d had CIA blazoned across his flight suit.  

Two farmers living nearby to the crash site were dissuaded from approaching with the terrifying news that the plane that had crashed had been carrying nuclear weapons – obviously, that wasn’t true, but it’s certainly a sure-fire way to keep people away from the crash site. Another way was through cash payments in exchange for silence. Apparently, $25,000 ($209,000 today) was paid to each member of the law enforcement team in the area, and it didn’t stop there. There were multiple stories of shady payments made in the coming years as the CIA attempted to keep the existence of the A-12 a secret.   

Three more A-12s crashed during testing. On 9th July 1964, “Article 133” ran into problems when a pitch-control servo mechanism froze at an altitude of 150 metres (500 ft). This resulted in the plane rolling to the left – exactly what you don’t want as you are just about to land. The pilot ejected, but because of the trajectory of the aircraft, he was blown sideways. Somewhat miraculously, considering the altitude and direction, his parachute opened, and he landed safely. 

On 28th December 1965, “Article 126” crashed just 30 seconds after take-off, due to a maintenance error. But again the pilot was able to eject safely. 

Things were not quite as lucky on 5th January 1967 as Operation Oxcart experienced its first fatality. No definite reason for the crash of “Article 125” was ever given, but most likely a fuel gauge error meant that the aircraft ran out of fuel still 108 km (67 miles) from its base. CIA pilot Walter Ray did manage to eject successfully but could not detach from his seat and died on impact.

Despite the numerous incidents, this was actually considered quite normal for an experimental aircraft like the A-12. It was quite simply operating at a different level than anything that had come before it, and occurrences like these were considered part and parcel of development. But by the early months of 1967, the U.S government believed the aircraft was ready – and it was time to ship out. But before we go into the real-world missions that this planes flew, let’s take a closer look at the aircraft itself. 


The A-12 is often compared to its successor, the SR-71 and looking at both from a distance they are almost indistinguishable. The A-12’s wingspan of 17 metres (55.6ft) is exactly the same as the SR-71, while its length of 31 metres (101ft) is marginally shorter than its younger brother. 

Left is SR-71A 61-7973, c/n 2024. Right is A-12 60-6924
Left is SR-71A 61-7973, c/n 2024. Right is A-12 60-6924

by Alan Wilson, is licensed under CC-BY-SA

As I mentioned earlier, the A-12 was considered a Mach 3+ aircraft, with a top speed of around 4,103km/h (2,550 mph) – which remains extraordinary even to this day. Concorde, which we always associate with record-breaking speed, had a top speed of 1,924 km/h (1,196 mph) less than the A-12.

Now, it must be said that much of the information around the A-12 is still classified. We have no way of knowing how often, or if ever, the A-12s needed to travel at this speed. Just to add to the confusion, the SR-71 has a slightly slower top speed, but still manages to beat the A-12 in some ‘fastest planes in the world’ list. This is probably because they only cover ‘official flights’ and as we’re going to go into shortly, the A-12 was a most unofficial aircraft. 

The A-12 also had a higher service ceiling, with a monstrous reported altitude limit of 29,000 metres (95,000 ft) – that’s not far off three times the cruising altitude of a passenger airliner today. Just to be really clear, that is 29km (18 miles) – straight up. We would need 35 Burj Khalifas, the tallest building the world, stacked on top of each other to get to that height. The SR-71 has a service ceiling of 3,048 metres (10,000 ft) less than the A-12 – which still easily makes it the second-highest altitude in aviation history.  

The A-12 was powered by two Pratt & Whitney JT11D-20B Afterburning turbojets, each coming with 20,500 lbf thrust dry and 32,500 lbf with its afterburner, which was often used during take-off and evasive manoeuvres. The SR-71 has the same kind of engine but with just under 5,000 lbf of thrust more than the A-12. You might wonder why the A-12 can be faster but with less power in its engines. This was probably down to the fact it was nearly 6 tons lighter than the SR-71.       


As I mentioned earlier, this aircraft was always designed to be able to spy on the Soviet Union – I mean who else were the Americans going to spy on in the 1960s? However, the downing of a U-2 over the Soviet Union in May 1960, and the subsequent capture of its pilot, meant that the United States was giving the USSR a wide berth at precisely the time that the A-12 came onto the scene. It’s a common misconception that the A-12 Archangel was involved in flights above the Soviet Union and Cuba. As far as we know, they never were. 

However, the United States had found itself in a completely new war, and the A-12 was sent to South-East Asia. Operating out of their base on the Japanese Island of Okinawa, the A-12s participated in Operation Black Shield, which was designed to get a clearer picture of the Vietnamese SAM missile defence system, military movements as well as general surveillance. On 31st May 1967, Operation Black Shield got underway with an A-12 flying at an altitude of 24,000 metres (80,000 ft) at a speed of Mach 3 (3,674km/h -2,283mph). Clearly, nobody was taking any risks at this point. 

Unfortunately, we don’t know a huge amount about the A-12’s involvement in the Vietnam War because much of it was, or still is, classified. But enough has been released to allow us to build up a basic picture.

The route profile for flights involved in Operation Black Shield was often roughly the same. The plane would take off from Kadena on Okinawa, before turning southwest. As I previously said, much of surveillance passes over North Vietnam was to determine the country’s missile defence system, as well as the position of roads, industry, ports, railroads and just about everything you could imagine. By the end of 1967, almost the entirety of North Vietnam had been photographed. 

A-12s returning would typically make an aerial refuelling over Thailand, before turning for Kadena once again. Interestingly, this route was said to have a turning radius of 138 km (86 miles), meaning that on occasions, returning A-12 would stray into Chinese airspace for a short period. Whether the Chinese knew about this is another matter, but there were never any reported incidents. 

Things were not quite so simple over Vietnam. As I’m coming to shortly, one reason that the A-12s had a relatively short life span, was the rapid improvement of Soviet radar detection – and as a consequence, North Vietnamese radar detection. 

On three separate occasions ground to air missiles were fired skyward at A-12s passing overhead, but only once did the United States come perilously close to losing their prized spy plane over enemy territory. On the 30th October 1967, at least 6 missiles were fired from around the capital Hanoi. The pilot reported seeing 4 of them gaining on him rapidly from behind, one came within 91 metres to 182 metres (10 to 200 yards) before detonating. The pilot thanked his lucky stars and continued on his way. But it had been an extraordinarily close call. A post-flight inspection found a piece of debris from a missile embedded under a wing, perilously close to the fuel tank. Flights over the area were immediately grounded, and wouldn’t begin again for 2 months. 


A front view of an SR-71 Blackbird aircraft being prepared for takeoff. The SR-71 is flown by Det. 4, 9th Strategic Reconnaissance Wing, 3rd Air Force, RAF Mildenhall.

The SR-71 arrived on the scene in 1968, and joined its older brother in Okinawa – but at just the same time the A-12 was going home. The American military saw no need for both aircraft, so to cut costs, the A-12 received an early retirement. 

But this wasn’t simply because the SR-71 was considered a superior aircraft. Much had changed since the design of the A-12 first appeared in 1960. In just eight short years the U.S had suffered the ignominy of losing a U-2 over Soviet Airspace, as well as witnessing enormous strides in enemy radar defences. The close calls that the A-12s saw over North Vietnam had shown that even at their extraordinary height and astonishing speed, they were still extremely vulnerable. The introduction of reconnaissance satellites, which began with the Corona satellite in 1959, showed that manned flights to gather photographs were no longer entirely necessary. 

Today, everybody knows about the SR-71 Blackbird – it has become a household name – as much as spy planes can do I guess. But what of the A-12? Not only was it faster and had a higher service ceiling, but it laid the very blueprint for the construction of the SR-71. Missing out the A-12 when discussing great spy planes is like going from a Robin Reliant to Lamborugini. Something definitely came somewhere in the middle. 

The A-12 has probably been a victim of its own classified nature. While the SR-71 was announced to the world in 1964, the existence of its mysterious older brother remained well under wraps for decades. The SR-71 may hold a catalogue of records, but is this simply because we’ve never known the full extent of the A-12’s escapades? We’ll probably never know. It may forever remain a thundering, elusive ghost of the skies.             

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