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If someone is jumping up and down in the bedroom of a private jet will the pilot be able to tell without listening? In other words, will the plane noticeably move?

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    $\begingroup$ If you jump up and down in my piper archer ill know.... $\endgroup$ – Dave Nov 15 '20 at 0:17
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    $\begingroup$ ...jumping up and down, in the bedroom? So that's what the young people call it nowadays? $\endgroup$ – jvb Nov 15 '20 at 20:55
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    $\begingroup$ @RockPaperLz-MaskitorCasket i guess it depends how tall you are... $\endgroup$ – Dave Nov 17 '20 at 1:02
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    $\begingroup$ @RockPaperLz-MaskitorCasket id say you jump up and down in a plane although you can jump up and down on a plane $\endgroup$ – Dave Nov 17 '20 at 1:04
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    $\begingroup$ @Dave I was teasing you a little because the last time I flew a Piper Archer, there was more room to jump "on" it than "in" it! :) $\endgroup$ – RockPaperLz- Mask it or Casket Nov 17 '20 at 1:26
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If an aircraft is large enough to have a “bedroom”, it will be too large for the movement of an average sized person in the bedroom to be noticed in the cockpit.

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    $\begingroup$ Now, if the plane is small enough.... A friend of mine was flying a PC-12 for a fractional ownership company one day and the part-owner customer and his girlfriend closed the cockpit door for some privacy, and he swears he could detect some "shaggin wagon" motion in the smooth air at cruise. At the end of the trip he was terrified to look the customer in the face because he was afraid he'd crack a smile, the wrong kind of smile, and it could have cost him his job. $\endgroup$ – John K Nov 15 '20 at 0:07
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    $\begingroup$ Oh that was sort of the scenario I was wondering about/ $\endgroup$ – Jorge Nov 15 '20 at 4:25
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    $\begingroup$ @DeanF - but what about TWO average-sized persons..? :-) $\endgroup$ – Bob Jarvis - Reinstate Monica Nov 15 '20 at 21:01
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    $\begingroup$ @DeanF. - alright, forget "jumping up and down". How about "swinging from a chandelier"? How about "going for a walk and a talk", eh? Listen -- strange women lying in ponds distributing swords is no basis for a system of government! Supreme executive power derives from a mandate from the masses, not from some farcical aquatic ceremony! You can't expect to wield supreme executive power just 'cause some watery tart threw a sword at you! I mean, if I went round sayin' I was an emperor just because some moistened bint had lobbed a scimitar at me, they'd put me away! $\endgroup$ – Bob Jarvis - Reinstate Monica Nov 16 '20 at 4:20
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    $\begingroup$ OP said nothing about the pilot actually being in the cockpit. $\endgroup$ – Mark Nov 17 '20 at 0:12
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That depends on how much the weight of that person force shifting (as a result of changing the center of gravity (CG)) as a ratio to the total weight force of the aircraft. If it's a tiny ratio then it will not affect the CG and thus will not change the aircraft attitude.

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Depends very much on the size of the plane and the position of the jumping passenger.

For example, a Cirrus SF50 has a maximum takeoff weight of 2722kg. An overweight passenger (let's take 150kg for the example) jumping really hard can probably exert a force similar to 300kg upon landing. That's more than 10% of the gross weight of the plane. If the plane is not fully loaded, the ratio will be even bigger. So, especially if the passenger is not jumping close to the Center of Gravity of the plane, this is definitively feelable.

Take the other extreme, an Airbus Airbus A380-800. This one has a maximum takeoff weight of 575 000kg. Here the 300kg of the passenger only represents around 0.05% of the weight of the plane. The only way the pilot might feel that is if the passenger is jumping directly onto the rudder and even then I'd be doubtful.

For the sake of the argument, let's say all passengers in an A380 jump at the same time (and in a coordinated fashion, since random jumping would equal out). The plane is certified for 853 passengers. Say, every one of them weights an average of 100kg, which is a lot, then we would have 85300kg of passengers. Double that weight to get a rough estimate for the jumping impulse and now you have 170600kg, which would come close to 30% of the gross weight. Again, very feelable.

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  • $\begingroup$ This answer brings me back to the question of scale. A smaller aircraft and a larger individual may have the respective mass in proportion to make the aircraft move in unexpected ways. But, an aircraft that small does not have the room required for a person that large to really jump up and down. Stomping up and down would be the most they could manage. $\endgroup$ – Dean F. Nov 17 '20 at 9:51
  • $\begingroup$ @DeanF. jumping from a squatting position and not straightening up fully could be quite effective. If they really wanted to cause trouble they could slam their feet down on landing, like breaking a plank by jumping on it. Of course I'm getting further from the OP's idea of "jumping up and down" $\endgroup$ – Chris H Nov 17 '20 at 11:18

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