Ever seen a model jet fly at 451 miles an hour?


Originally published at: https://boingboing.net/2017/10/29/ever-seen-a-model-jet-fly-at-4.html


Reminds me a lot of pictures of WWII German V1 buzz-bombs.


Bah. Current record is 520mph. according to rcspeeds.com.

With a glider


Fun fact: 451 mph is exactly the speed of burning paper!


That was awesome in the original sense of the word.

It got me to wondering though. China supposedly has an air-to-air missile that can go mach 6 and others have been going at mach 2 and above for decades. If hobbyists can build a model jet with a kerosene engine, why can’t someone build an RC plane with a missile’s rocket motor (minus the explosives obviously)? If the guidance system on a missile can keep it stable enough to home-in on a fighter jet, why couldn’t it keep it in the air long enough for a test flight?

In fact, aren’t military drones basically RC jets with encrypted satellite links and fancy accessories? They can break the sound barrier.

I guess my main question is, if cost is the only divider between model jet and drone jet, what is the threshold, is it arbitrary, will hobbyists cross it, and when they do will the threshold move or will the distinction disappear?


There is a point at which the speed exceeds the ability to control, or even see what you’re flying if you’re just some guy with a remote on the ground.

As for where the limits of hobbyists planes can go, I believe the FAA has something to say about that.


I’m just curious if there’s a distinct engineering difference between a military drone and an RC jet, or if it’s just a divide people have decided on through laws, club rules, ect…and if the line ever moves.

Isn’t a military drone being flown by a guy with a remote on the ground with higher clearance and more sophisticated hardware? That is to ask, is there a fundamental engineering difference between the two, or merely a difference of degrees?


I think GPS guidance, autopilots, and gyroscopic stabilization are not found on these civilian fixed wing models typically flown “seat of the pants”. Multifan drones on the other hand do feature most of that.


“Want to see it again?”


That’s a pretty damn expensive bit of kit, considering it has pretty much zero utility beyond being a toy.


I can think of plenty of just as impractical hobbies that make that look cheap.


My thoughts exactly. What’s the range, and how much explosive can I put in it?

Although, at over 200 m/s it could make a significant dent in most civilian vehicles even without explosive. At this point I will keep speculation about what kind of vehicles in the confines of my head. Unless I write a short story, or an NCIS script, about it.


There are controllers out there for hobby RC fixed wing aircraft. They’re relatively simple but the do exist.


One wrong turn and it’s out of RC range in seconds.


How come the entries you want to be advertis–uh, “sponsored content” for the Boing Boing Store never are?


Would you people please shut up? It’s hard enough trying to stop bureaucrats banning models as it is.


Yep, you could.

Supersonic aircraft typically fly higher because they are more efficient in thinner air, but you can do sonic booms near the ground, as that is what they used to do in air shows when supersonic aircraft were new. The air craft shape would have to be a lot more polished, as the finish critically affects the point where the shockwaves detach. Concorde had a deliberately rough strip on the wing upper just to fix the detachment point in one place rather than have it find it’s own position. This is particularly important as you go through the speed of sound: the airspeed is different for the top and the bottom of the wing, so there are all sorts of flips in flow geometry, though this may not be too much of a deal if you can accelerate through that speed. But that taped-up bit near the tail would never do.

But would it be fun to fly? Or would it be like the Bloodhound 1000 mph car, which is effectively a rocket with wheels flying parallel to a specially chosen bit of ground, rather than into it or above it, if all goes well? Flying a supersonic model would be pressing the throttle and trying to keep in a straight line. That would probably have to be done by computer, as human reactions would probably be too slow at the model’s smaller time scale.

But look at this - he’s flying using flaps and throttle, and it’s like Windhover. And look at that landing - that was so sweet! If I landed that just using flaps and throttle controls, you would need a spade to find it. Nope: biggest speed isn’t always best.

(raises hat)


There was that guy in New Zealand building a GPS-guided ‘cruise drone’ back in the early 00s. The government there made him stop.


Which reminds me of the old Dynajet pulse jet motors. Little pulse jet motors using the same basic design as the V1 buzz-bombs by scaled down for model airplanes. They got very hot but worked pretty well.


If I tried to fly an R/C plane that fast, a Rapid Unscheduled Disassembly would be almost a given.