The nozzles of the Sukhoi T-50 seem to be aligned not perfectly parallel. However, it is not very pronounced.

What may be the reasons for aligning the nozzles engines not perfectly parallel.

Edit: in my original post I asked about the nozzles, however, as it was pointed out, this plane used 3D thrust vectoring, so the nozzle arrangement might be this way by chance. However, also the engines seem to be aligned not perfectly parallel. The question has been edited accordingly.

Suchoi T-50 Image source Wikimedia

Edit 2: Here is another picture of a PAK-FA with a Mig-29 Image source, Wikipedia again

  • 1
    $\begingroup$ Might be the thrust vectoring being used. $\endgroup$ Commented May 28, 2016 at 11:26
  • 2
    $\begingroup$ You might clarify if you're actually talking about the nozzles, in which case Adder's answer applies. But looking at aircraft photos I think you are probably asking about why the entire engines are skewed slightly apart. $\endgroup$
    – TomMcW
    Commented May 29, 2016 at 2:54
  • $\begingroup$ Good point about the engines. Initially it was the alignment of the engines that triggered this question. However, it got formulated to be about the nozzles, which is not the same for 3D thrust vectoring aircraft. $\endgroup$
    – Dohn Joe
    Commented May 30, 2016 at 20:45
  • $\begingroup$ Regarding your edit, this might just be the paint job playing tricks on you. $\endgroup$
    – Sanchises
    Commented Jun 2, 2016 at 8:40
  • $\begingroup$ @sanchises: I am not sure if it is solely an illusion. Compared with other planes, e.g. the Mig-29 the engines of the Pak-FA seem not quite parallel. $\endgroup$
    – Dohn Joe
    Commented Jun 5, 2016 at 12:58

1 Answer 1


The Sukhoi T-50 operates Thrust vectoring nozzle control at low speeds. The nozzles are a part of the Fly By Wire system and will deflect as per the control input given by the pilot. The nozzles move in coordination with other flight controls and it is not necessary for them to be parallel in all conditions of flight. However on the ground they will appear to be parallel.

  • $\begingroup$ To add to this, it's actually a condition of the PAK-FA nozzles that they're not parallel. Otherwise they wouldn't be able to perform 3D thrust vectoring (as they'd lack moment in 2 of the axes). $\endgroup$
    – os1
    Commented May 31, 2016 at 16:58
  • $\begingroup$ Depends on the degrees of freedom the nozzles have to move. There are different types of vectoring nozzles. $\endgroup$
    – user7241
    Commented Dec 23, 2017 at 22:24

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