[wrp]

They are tube-fired, so maybe it's so they don't have to be oriented for firing. I'd like to hear an explanation of the aerodynamics of the wing arrangement, such as how it affects flight stability. I've never seen anything like it.

[techdragon]

Its aerodynamically simpler to have reliable control of a symmetrical system like this. Your pitch and yaw control are the same and your roll control becomes not “unnecessary” but definitely not as critical for controlling the flying craft as it is with “traditional” asymmetric combinations of wings, canards, tails, and other aerodynamic surfaces.

It’s actually pretty easy to experiment with if you have a copy of kerbal space program. Make a “wing tip sitter” with a single fuel tank, engine, and airplane cockpit, then use swept wings with landing legs to keep the engine off the ground and then fire it up and take it for a spin and see how it can “freely” manoeuvre in any pitch/yaw direction and you can remain stable in your flight regardless of roll,

This allows a tube launched system to just pop out the wings and immediately begin manoeuvring based on internal sensors with zero visual ground/sky needed. It’s ok to “level off” immediately at the desired altitude and then immediately turn towards the desired heading and proceed to target. It’s not as aerodynamically efficient (extra wings add mass and in the optimal lift orientation don’t add more lift) but it is more manoeuvrable and that’s valuable in a missile.

If it helps to understand the trade off… You see more traditional wing designs with longer ranged missiles (like Tomahawk cruise missiles), even tube launched ones, where the lift efficiency is desired they design two larger wings in the middle like a “normal airplane” to have the maximum possible lift for their desired speed/drag/weight/size and then have smaller fins at the back for stability with steering by some combination of manoeuvring surfaces and/or engine thrust. They trade the manoeuvring power of this “x” design for the more efficient long range performance of a more traditional wing design.

[wrp]

This is really cool. I'd like to read more about this approach. Are there also non-military applications or hobby drone designs?

[techdragon]

I can’t find the videos or channel because google search is so useless these days. But I have seen some DIY drone designs that used unusual configurations. One that comes to mind was a triangle/y shaped tri rotor drone that cut power to one “arm” and basically switched modes like a tilt rotor airplane. By using the upper two motor supports as wings to generate lift it was able to fly forward with lift at one third the power… and i think they used some clever torque balancing between the arms to get a similar effect as traditional counter rotating propellers.

There’s a lot of innovation going on in DIY drone design at the moment, the challenge is actually finding it and following it as it’s all distributed across random reddits, forums, social feeds, patreon updates, and YouTube channels… I’m sure someone dedicated to following the field can probably keep on top of it but I’m more of a space nerd than an airplane nerd so i get exposure to these neat designs mostly by random chance due to lots of the various social and search algorithms lumping everything under “aerospace”.

If I’m remembering it correctly he was experimenting with the drone not having a preference for which motor support arm was “down” and having the drone control software automatically transition based on the current attitude and velocity, so he could “drop” to forward flight mode and have one arm dip, or manually fly it “over” into the mode and have it switch automatically. Seemed very clever. But while it was in “tri-rotor” mode it had similar aerodynamic properties to the X shaped wing designs due to the Y shaped wing design also having symmetry around the roll axis.