Most if not all jumpjets (and jetpacks) in any genre have some kind of neural link or unexplained control mechanism that might as well be a neural link. However I want to have a controlscheme for my jumpjet with several requirements:

  • it has no neural link
  • its controlscheme is known and explained
  • the controls leave the hands free to handle objects, such as carrying someone in their arms during a rescue*♤
  • the jumpjet needs to be able to perform the following maneuvers:

-- jump. The jumpjet launches in the air, the user needs to control how long this jump takes to make sure they reach the height necessary (or dont reach too high).

-- "hover". The jumpjet uses its propulsion to maintain height/slow down the descent and control the arc of the jump.

-- land. The user needs to be able to stop the horizontal and vertical speed for a safe landing, requiring a potential strong burst to slow down at the last moment.

-- control direction. The jumpjet user needs to be able to correct for miscalculated jumps, wind or pick an entirely different direction, possibly even backwards.

-- the user should not be at high risk of accidentally activating the jumpjet. You dont want to start a jump by accident indoors for example.

I am OK with controlschemes that do not satisfy all of these since its probably a tall order, but the question that satisfies most of these points will be accepted.

*how and where the propulsion is located is not relevant for the question, assume its well-designed.

this means that any weight distribution controlschemes are not possible as it would unbalance the jumpjet towards the weight you are carrying!

  • 1
    $\begingroup$ There is always the option of Mr. Garrison's "It" control mechanism. "Still better than dealing with the airlines." $\endgroup$
    – John O
    Commented Mar 4, 2022 at 17:33
  • $\begingroup$ @JohnO care to explain for the people who haven't seen the movie? $\endgroup$
    – Demigan
    Commented Mar 4, 2022 at 19:56
  • 3
    $\begingroup$ @JohnO please don't. Some of us, at least, still have the opportunity to never know. $\endgroup$
    – Qami
    Commented Mar 4, 2022 at 21:59
  • 1
    $\begingroup$ Due to @Qami 's honest request, I will not explain. Those who have to know have enough keywords to discover for themselves. $\endgroup$
    – John O
    Commented Mar 4, 2022 at 22:59

6 Answers 6



It's very quite simple. If hands and brain are out, then the feet is the preferable solution. To ascend, point your toes downwards. To descend, point your toes upwards. (This is based off the motion of driving a car - pushing your foot down is linked mentally towards triggering something.) To control direction, rotate your feet. Seems simple enough.

The only downside is that feet are commonly used for walking - so how do you prevent the jet from firing accidentally? The trick to this also seems simple enough - curling your toes. While walking/sprinting/jogging, a human does not curl his toes, it is an unnatural act. And a human especially will not curl all 10 of them at once unless fully deliberate. So the the trigger for the jet is to curl all 10 toes at once.

  • $\begingroup$ Thank you for adding the constraint I forgot: make sure it doesnt go off by accident. I added it to the question. I was also thinking about feet, but in the hopes of getting an even better answer: how can you prevent accidental course corrections? When changing course with your toes curled your legs are at risk of swinging with the movement causing flight issues. How wiuld you stop that? $\endgroup$
    – Demigan
    Commented Mar 4, 2022 at 19:51
  • $\begingroup$ @Demigan Don't curl your toes when changing course. $\endgroup$
    – Halfthawed
    Commented Mar 4, 2022 at 21:15
  • $\begingroup$ but you need to curl your toes to start changing course right? The moment you can control the jumpjet by rotating your feet you run the risk of your legs swinging about and causing wrong course corrections! $\endgroup$
    – Demigan
    Commented Mar 5, 2022 at 6:58
  • $\begingroup$ @Demigan that’s something for the training to deal with, and of course it has an automatic system to prevent you from crashing into something too hard. $\endgroup$
    – Topcode
    Commented Mar 5, 2022 at 23:59
  • $\begingroup$ ". . . how do you prevent the jet from firing accidentally?" It is called an on/off button my friend. $\endgroup$
    – Daron
    Commented Mar 7, 2022 at 13:42

Tongue Operated Drive System

Frequently, when looking to solve a problem like this, it helps to take a look at how it's been solved in the real world, e.g, enabling people with quadriplegic paralysis to control devices. An interesting recent example, discussed in Tongue-Operated Assistive Technology with Access to Common Smartphone Applications via Bluetooth Link is the tongue drive system, which uses an inset-palate device like so: enter image description here Credit to The Verge

The basic set of controls here is intended for click-like interfaces, e.g, interfacing with a phone, but there's no reason it couldn't be adapted for something more like a flight control. Using a specific tongue motion (A repeated tongue click, perhaps?) to initiate the controls (along with tactical feedback when that happens to prevent accidental activation).

  • $\begingroup$ Its a nice system, but how do you control the amount of thrust you give? These buttons only give you an on/off switch (as far as I can tell reading the article), not a throttle. Although if I combine your idea and Halfthawed's idea it could work: feet determine throttle, tongue to determine direction. Perhaps if you can pinpoint the tongue location you can give more analogue control over steering as well. $\endgroup$
    – Demigan
    Commented Mar 5, 2022 at 7:11
  • $\begingroup$ “The basic set of controls here is intended for click-like interfaces, e.g, interfacing with a phone, but there's no reason it couldn't be adapted for something more like a flight control.” For thrust, I’d recommend something like a continuous electro capacitive strip along the inside of the teeth that lets you ‘drag’ the tongue up or down along it to increase or decrease velocity. $\endgroup$
    – Daniel B
    Commented Mar 5, 2022 at 13:58

A PID controller solve most of your concerns

Modern robotics are impossible without the use of feedback compensation systems. You cant just tell a system "do this much thrust" and ever expect it to work in the real world; instead, automation engineers use use gyro sensors, radio triangulation, and optical sensors in their their devices to detect any difference between where a part of a mechanism is in the real world, and where it should be according to its programming. (Optical sensors are especially useful in this case for determining things like when to slow down as you approach the ground for a landing.)

The PID controller changes the proportional trust of any components to get it to where it should be. So, if you were to pick up a heavy load like another person which offsets your weight, the PID controller would notice the lean caused by the extra weight and re-adjust the thrust balance appropriately to keep you flying straight and steady. So all of your concerns about a piolet needing to focus on weight distribution are easily dismissed assuming a setting with current or better technology.

If your flight is more of a single powerful impulse than a sustained thrust, you can put force sensors into your boots. That way you know your exact payload and approximate weight distribution before takeoff. Then once in the air, your flight control only needs to make minor adjustments to bring you down safely and on target.

Fine motor control is paramount

While there are all sorts of ways to control a device without your hands (bite sensor, tongue sensor, eye movement sensor, voice command, etc.) When you are talking about a device that propels you through the air at high speeds without so much as role bars or a seat belt to save your life if something goes wrong, your top priority should be to have an interface that allows you the most precise and responsive control possible. With the user's life on the line, all other considerations should be considered secondary. When it comes to fine motor control, a persons hands will always be leaps and bounds more performant than any other physical interface you can chose. So the question then becomes not how to make the system hands free, but how to do other stuff while using your hands to control your jump jets.

While the OP does not mention why this person is using jump jets, we can generally assume it's because this person is some kind of solider, emergency responder, or tradesmen who just needs too get to a hard to reach place that people don't normally need to think about reaching in our day to day lives. So, this person likely has some tool of the trade that is already expected to occupy 1 or both hands. This could be a gun, a fireman's hook, a medical kit, a squeegee... does not matter. My point is no one ever needs to use jump jets unless they have some problem to work on when they get there, and for that they generally need a tool. So, just install the controller into whatever this tool of the trade is.

How to design the interface

You will probably want a 3 factor safety like you see on many power tools just to make sure it does not go off by accident. So, one safety switch that is well out of the way that unlocks the system, when you know you are about to need it. Then require the pressing of two things at once to start it (Like R1 + Analogue shown below).

Once started, your control of the flight system is very similar to a half of a gaming controller. An analogue stick for your thumb lets you you steer while 2 finger buttons allow you to increase or decrease thrust/height. You could also add a few key combination macros like a double tap "up" to give your more of a jump than a controlled flight mode.

enter image description here

As for carrying someone while using this, people like soldiers and fire fighters carry people all the time, and they do it without leaving behind their tools or weapons; so, assuming your protagonist is in decent shape, he could sling a person over his shoulders, and clamp the leg and arm with the tool in hand so as not to drop them, and then control the jump jets from more or less this stance:


If for whatever reason you do not have any tool-of-the-trade, just carry a 1-handed game pad in your pocket and you can put all the same controls onto it, and then some. You can still carry things in both arms while manipulating something like this in your one hand.

enter image description here

  • $\begingroup$ Although against the constraints and not useable for my story, it can be useful for someone else's. Imagine that instead of on the tool, its part of a glove and the control surface can be loosened to be stuck to the tool at hand. That way if you arent holding your tool you still have the control surface at the ready inside your hand. The PID would be necessary anyway for reasonably stable flight without flipping, but I am still not sold on a complete weight distribution steering system yet (besides again I cant use one for the story at hand). A quick jump for example gives little time to alter $\endgroup$
    – Demigan
    Commented Mar 7, 2022 at 19:12
  • $\begingroup$ @Demigan place force load sensors in each boot. That way you can get the weight distribution before you take off... and if there is no tool of the trade to worry about, then there just carry around a little hand-held controller in your pocket, kind of like the detachable half controllers on a Nintendo Switch. $\endgroup$
    – Nosajimiki
    Commented Mar 7, 2022 at 21:30

Skateboard style.



You pilot a skateboard using your legs and body, and leg motions relative to the body. Arms and hands are free though can be used to shift center of gravity.

If you need to rescue someone while skating you can keep skating.

catches child https://www.youtube.com/watch?v=9UcJ0MsS3fg

Having your character ride a jump jet like a skateboard (maybe a snowboard because of the straps!) would open a range of actions that will be familiar and foreign at the same time which makes for fun fiction. Also you can borrow from the lingo of skating / boarding and apply those terms for your jumpjet corps.

  • $\begingroup$ I'm not certain how you will control this exactly? It might help give some leeway for weight distribution controlschemes (but only for reverse pendulum style jet placement), but how do you differentiate between walking and a jump? How do you adjust power during a jump? Or the length of time active? How do you go into and out of the hover mode? How do you activate a measured landing burst? $\endgroup$
    – Demigan
    Commented Mar 7, 2022 at 12:20
  • $\begingroup$ @Demigan I am going to refer all those questions to Marty McFly. $\endgroup$
    – Willk
    Commented Mar 8, 2022 at 0:27
  • $\begingroup$ Marty does not change height, arc and speed (speed only by touching the ground during push-off). How would you do that skateboard style? $\endgroup$
    – Demigan
    Commented Mar 8, 2022 at 6:29

Remote control

Someone else is doing the driving for you, so you can concentrate on other things such as shooting or holding someone else. The jumpjet is in effect a drone with a very special format, controlled by your buddy. You should hope that they know what they are doing.

  • $\begingroup$ While its an out-of-the-square-cube thought it kinda glosses over the "user in control" part. $\endgroup$
    – Demigan
    Commented May 4, 2022 at 20:16

Voice control and eye tracking You can give voice commands to the computer controlling the jumpjet. It has multiple microphones so that it can triangulate all sounds and make sure commands come from the right source. You can refer to where you are looking. Even if it's not the main control method it can be used as a backup if you have your hands full. Examples: "Hover 20 m". "Go east". "Go to that car".


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .