Civilian jet airliners don't need to push their yokes down to follow the curvature of the Earth because within the atmosphere the curvature is accounted for by automatical systems, right? I wonder whether there are jet aircraft (from the military, obviously) that actually have to push their yokes down for instance. The SR-71 Blackbird flew very fast (more than Mach 3) at very high altitudes (above 80,000 ft). Did Blackbird pilots have to be careful not to fly too much up due to the Earth's curvature, respectively not to cause a stall? Did Blackbird or other jet's pilots need to take other astrodynamics into account, such as rotational forces or other pitch concerns?

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    – Federico
    Commented Sep 23, 2020 at 17:56

1 Answer 1


It's the same question as for the ISS in orbit, gravity is pushing the yoke down for you. When you fly level you're actually keeping your distance from the earth center constant.

  • $\begingroup$ But the nose pitch remains the same relative to the stars while not remaining the same relative to the surface. Therefore, it goes more and more up, till the threat of a stall. $\endgroup$
    – Giovanni
    Commented Sep 20, 2020 at 18:13
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    $\begingroup$ No you adapt your nose pitch to remain at constant density altitude. $\endgroup$
    – MaximEck
    Commented Sep 20, 2020 at 18:29
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    $\begingroup$ The ISS is moving at orbital velocity - crazy fast. Even the fastest aircraft is moving, even with Earth's rotation, far slower. Apples to Oranges comparison here. $\endgroup$
    – Ralph J
    Commented Sep 20, 2020 at 19:04
  • $\begingroup$ The SR-71 went to 3500km/h; low Earth orbit is at 28000km/h. Indeed apples to oranges. $\endgroup$
    – Sanchises
    Commented Sep 20, 2020 at 19:35
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    $\begingroup$ He is asking if an airplane will pitch up if flying level, thinking that the airplane will go on a straight line and at some point leave earth atmosphere by doing so, which to me is similar to leaving earth gravitational field. I'm answering that even the ISS at 400km and orbital velocity around our planet is not capable of doing and then explain what flying level actually means... $\endgroup$
    – MaximEck
    Commented Sep 20, 2020 at 21:59

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