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I recently went to the museum in Sinsheim, Germany, where a Tupolev Tu-144 is on display. I noticed that the landing gear of this plane is actually way wider than the space it has available when retracted. How can this work? Does the gear fold before retracting?

Sadly, I wasn't able to find any video footage of the TU-144 retracting its gear. Please take a look at the picture I took to understand what I mean:

Enter image description here

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    $\begingroup$ google image search for 'tu-144 landing gear' gets some pretty decent explanations, did you try searching before asking here? $\endgroup$ – egid Apr 20 '16 at 6:17
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    $\begingroup$ And now this very question is search result number 4 on Google, and will likely move up higher now that it has a couple good answers. I don't see any problem with asking on-topic questions that have easily found answers on Google, it helps build up Stackexchange as a knowledge base and helps with self-referential answers, so when someone asks "How can landing gear that's too big fit into the landing gear bay?", the answer can link to this answer instead of having to link to external sources that may not always be available. $\endgroup$ – Johnny Apr 21 '16 at 2:37
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The Tu-144 uses much smaller wheels than comparably-sized subsonic aircraft. This makes it possible to rotate the gear bogie sideways towards the middle of the aircraft, so it can be stowed vertically inside the wheel well. Your picture already hints at that: Note that the gear strut is offset inside the wheel well, so it would leave more space on one side for the gear bogie.

Tupolev Tu-144 landing gear

Tupolev Tu-144 landing gear (picture source). Note the big drums of the wheel brakes: They were needed to stop the aircraft - the engines had no thrust reversers! Inside are stacks of disc brakes to absorb the energy that comes with a landing speed of 270 km/h. Also note the unusual sideways arrangement of the scissors link: This way it did not interfere with the rotated wheel bogie. Next clue: The big hydraulic cylinder on the left was used to pivot the bogie around an axis parallel to the direction of flight.

Photo from Tu-144 landing gear test

Picture of a photo from Tu-144 landing gear test, including finger print (picture source). This shows the gear in mid-sequence: The bogie is already rotated and lies sideways, with the gear strut between the wheels. Now the strut pivots forward and up into the wheel well.

Requiring complex motion adds more failure modes: On its 59th flight, the XB-70A suffered a malfunction of the left gear which left the bogie in the upright position. If you want to know how it was supposed to work, watch this video from 14:47 on. The picture below is taken from this video.

XB-70A after flight 59

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    $\begingroup$ What do you mean when you say "including finger print"? $\endgroup$ – David says Reinstate Monica Apr 20 '16 at 12:52
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    $\begingroup$ @DavidGrinberg: The picture is of an old print. It shows the reflection of a lamp on the top left and a finger print on the top over the gear doors. Also, the lower edge is warped - the print was not lying flat when it was digitized. $\endgroup$ – Peter Kämpf Apr 20 '16 at 14:37
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The Tu-144 landing gear rotates 90 degrees when retracted up between the engines.

enter image description here

Source: Tu-144 Landing Gear Retraction

enter image description here Source: Tu-144 Landing Gear Retraction

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    $\begingroup$ That actually worked?.... Oh, those Russians... $\endgroup$ – Oscar Bravo Apr 21 '16 at 13:32
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    $\begingroup$ @OwenBoyle Even the guy in the middle looks skeptical $\endgroup$ – thanby Apr 21 '16 at 13:41
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    $\begingroup$ The North American XB-70 also had a very strange method of gear retraction: youtube.com/watch?v=0d6VmbwOoek $\endgroup$ – Mike Sowsun Apr 21 '16 at 15:57
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    $\begingroup$ XB-70 gear swing: youtu.be/seWJa6SG3LQ?t=4m48s $\endgroup$ – Mike Sowsun Apr 21 '16 at 16:01
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    $\begingroup$ Please tell me this gear retraction process is only the first step in reconfiguring the aircraft as a giant humanoid robot. $\endgroup$ – Henning Makholm Apr 21 '16 at 22:02

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