Legend has it that dummy blueprints for the Concorde, featuring design errors, were created to fool Soviet agents - and that the USSR's supersonic airliner, the TU-144, featured some of these flaws. Is that true?

It's interesting that your name is /u/JournalofFailure, because that's what I have to report. This journal of failure is both my own -- I have no smoking gun to firmly answer your question -- and that of the Soviet Union, which manufactured the TU-144. Allow me to present the evidence, and at the end, I'll give you my conclusion. There is no TL/DR, because this isn't Buzzfeed, and you're a fucking adult.

I imagine there's a lot of you who aren't familiar with the TU-144, even if you've heard of the Concorde. Let's do a quick recap. Back in the 1950s and 1960s, aeronautical engineering was caught up in the spirit of "faster, farther, higher." Engineers and the public were interested in the next leap forward in aviation and space. They wanted aircraft that would press the limits of the cutting edge. Mundane things like passenger comfort, fuel efficiency and economics were considered rarely, if at all.

In the late 1950s, the United States, the Soviet Union and European nations independently began projects to develop a supersonic airliner. The American model was the Boeing 2707; it never flew. The Soviet Union announced its plans quietly at the start of 1962. Owing to the high cost of designing and building a supersonic transport, the British and French governments agreed to cooperate. In the spirit of cooperation, they agreed to name their aircraft Concorde, the French equivalent of the English word "concord," meaning agreement.

Through the 1960s, the Soviet, American and European teams advanced their designs. On Dec. 31, 1968, the Soviets wheeled out their prototype, the Tupolev-144, for its maiden flight. The first flight was conducted with no announcement -- the Soviets wanted to be able to conceal it if it failed. It didn't fail. The Tu-144 made three passes over its airfield in a flight lasting 28 minutes, and pictures of the Soviet aircraft were flashed around the world, trumpeting the Soviet technological triumph.

Where the Soviet aircraft had been developed quietly, the Concorde had been developed in public, and even before its maiden flight in March 1969, its distinctive shape was well known. Thus, when images of the Soviet aircraft were released and compared to that of the Concorde, it was no wonder that the Tu-144 soon became nicknamed the "Concordski."

While they looked similar on the surface, the Concorde and Tu-144 had their differences. Though they both had a drooped nose and delta wing (and indeed, so did the Boeing 2707), the Tupolev's wing was less sculpted. Its engine pod was beneath the cabin, not the wings. Its cockpit instrumentation, cooling system and internal structure was different.

For the next four years, both the Concorde and the Tu-144 were tested and refined. The Tupolev had problems with control at low speed, so engineers added a swinging set of canard wings, tiny flaps just behind the cockpit that could be extended to aid control at low speed. The Tupolev landed faster than the Concorde, but it was faster in the air. It could carry more passengers and more cargo. With the cancellation of the Boeing 2707 project in 1971, there were open questions about whether the Concorde or the Tu-144 would dominate the future of air travel.

The 1973 Paris Air Show was poised to be the showdown.

The annual air show is an impromptu aircraft showroom for buyers and sellers. It brings together the airlines and air manufacturers. In the past, it's been used as a venue for attempts to set airspeed or altitude records. It's also a huge tourist attraction and viewed by millions of people who travel to Paris just for this event.

The Concorde performed its demonstration flight first, and it did so flawlessly. The Tu-144 taxied into position, and the French suddenly radioed that its demonstration time would be cut in half -- a last-ditch attempt to shame the Soviet aircraft against its half-French competitor.

What came next changed aviation history.

After the crash of the Tu-144 in Paris, the two aircraft had markedly different histories. The Concorde went on to limited commercial success, serving trans-oceanic flights until 2003. The Tu-144 was a commercial flop, making only 55 scheduled passenger flights. It later became a testbed for supersonic flight (including NASA-run missions), and that may be its biggest success.

But I haven't answered your question yet. For that, you'll have to move on to the next comment, because I've run out of space ...