
RC fighter model UAV build in Jet engine 360+mph [video] - MichaelAO
https://www.youtube.com/watch?v=Uz8SjWnVSBs
======
kator
Does it worry anyone that he looses this thing in the clouds on a regular
basis? Seems irresponsible to fly it on a day where you can't keep it in view.
With this much speed it's basically a flying remote controlled
rocket/projectile that would kill someone instantly if it hit them.

I wonder how this thing handles loosing contact with the controller?

It's no wonder the FCC in US is getting less and less RC friendly, besides the
typical "home land security" drama stuff like this in a public park could be a
real problem from noise pollution to safety of other people in the area.

All this said, must be quite a rush to play with something like that, I would
love to fly it in an open field deep in the desert with a clear open sky.

~~~
baddox
If you saw a video of someone flying a full scale aircraft without incident,
would you assume by default that they are being irresponsible? I don't think
most people would say "that seems irresponsible since it's basically a huge
flying missile that could kill dozens of people if it crashed," even if the
full scale aircraft was flying in very low visibility conditions.

~~~
kjs3
Your grasp of false equivalence is impressive.

~~~
baddox
What about the analogy do you think is flawed?

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matheweis
This is an old video; the original is from over five years ago:
[http://youtu.be/dTHWBSluUjU](http://youtu.be/dTHWBSluUjU)
[http://www.rcuniverse.com/forum/rc-jets-120/9133201-fast-
rc-...](http://www.rcuniverse.com/forum/rc-jets-120/9133201-fast-rc-jet.html)

Either it's a rip off or somehow "Jukin Media" got the rights to it... It
never ceases to amaze me when old stuff goes viral like this. Maybe it's the
keywords stuffed in the title, 'cause UAVs are a pretty hot topic these days,
but this thing is not a UAV.

~~~
thisjepisje
How is this not an unmanned aerial vehicle?

~~~
phil21
Because UAV has certain connotations in normal parlance. It's like saying that
strange plane you haven't seen before is a UFO. A technically accurate but
useless description if you want people to understand what you mean.

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ajross
This appears to be the engine in question:

[http://www.jetcatusa.com/p160.html](http://www.jetcatusa.com/p160.html)

Executive summary appears to be: 36 lbs of thrust with a (dry?) weight of 3.1
lbs and a fuel consumption of about a pound per minute. Sounds shockingly
good, so I have to wonder if the compressor is basically an ablative heat
shield and this is good for only a few runs.

That said: doing this stunt in what looks like a suburban park strikes me as
shockingly irresponsible. This thing can easily kill someone, wreck a vehicle
or puncture a roof if control is lost...

~~~
chrisan
> That said: doing this stunt in what looks like a suburban park strikes me as
> shockingly irresponsible. This thing can easily kill someone, wreck a
> vehicle or puncture a roof if control is lost...

I'd be more concerned with drunk or texting drivers than a R/C jet engine
killing me.

~~~
SandB0x
I'm more concerned with drunk or texting drivers than getting eaten by a
tiger. Does that mean I shouldn't be worried if someone lets a tiger loose in
the park?

~~~
baddox
What if there's a tiger with a team of professional large animal trainers
abiding by all sensible guidelines?

~~~
demarq
except for letting loose the tiger in the first place.

~~~
baddox
The hypothetical situation I'm proposing is if the tiger is _not_ let loose,
but is being tended to by experienced people.

~~~
lotsofmangos
We should also calculate the risk if the tiger was being flown round the park
on a jet powered drone, just to cover all bases.

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Aardwolf
How do you control that? It goes so fast a fraction of a second mistake could
be fatal, and you can't see it half the time.

~~~
frik
A good eye sight is several times better than the resolution of the video
camera. You need a fast reaction time and good 3d orientation sense. You can
train that with simulators & video games.

~~~
bigiain
And, of course, a string of previous versions of this sort of rc plane.
Without anything except that footage, I can say with 100% certainty that this
is not the first rc plane that pilot has flown. I'd be quite surprised if his
list of planes before this one didn't approach or exceed 100... (I'm nowhere
near ready to fly something like that, and I could list 30 or 40 models I've
built and flown).

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mattivc
I have been toying with the idea of trying to create a small Pulsejet[1]
engine and stick it on a UAV frame. It's a very simple design and shouldn't be
to hard to make with, i think.

[1]:
[http://en.wikipedia.org/wiki/Pulsejet](http://en.wikipedia.org/wiki/Pulsejet)

~~~
bigiain
Apparently these work OK:
[http://hobbyking.com/hobbyking/store/__37414__Hobbyking_Puls...](http://hobbyking.com/hobbyking/store/__37414__Hobbyking_Pulse_Jet_Gasoline_Engine_34_Red_Head_34_.html)

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ChuckMcM
Interesting discussion, clearly the size and speed crosses the 'scary'
threshold. I wouldn't worry too much about that however as the risk is small,
people invest a lot of time and effort into building models and that
investment means that it is very very painful for them if they crash them. In
many ways the modeller has more invested in the outcome than onlookers or the
folks in the area.

That said, its an amazing to me this guy can keep his head 'in the plane'
which is to say at that speed can fly the plane to its orientation rather than
his own. When I've flown model planes there are always times where I'm turning
the wrong way because I've mixed up the front back / left right controls given
a particular plane attitude and direction. (and yes crashed a couple which
made me feel horrible and so I stick to vehicles :-)

Next up I hope someone can build a FPOV version so they can fly it from the
"cockpit". That would also make for a great video.

~~~
baddox
> That said, its an amazing to me this guy can keep his head 'in the plane'
> which is to say at that speed can fly the plane to its orientation rather
> than his own.

If you think the orientation skills in this video are impressive, you should
check out the professional 3D RC helicopter pilots!

[https://www.youtube.com/watch?v=KuDptulCpK0#t=37](https://www.youtube.com/watch?v=KuDptulCpK0#t=37)

[https://www.youtube.com/watch?v=PptMrBFAO-A#t=28](https://www.youtube.com/watch?v=PptMrBFAO-A#t=28)

[https://www.youtube.com/watch?v=QDxaJTjCFhE#t=16](https://www.youtube.com/watch?v=QDxaJTjCFhE#t=16)

~~~
jgable
You got that right. I tried RC heli flying for a little bit. Spent several
hours flying in the sim and several more flying the real thing, and could
never comfortably do a nose-in hover. Very humbling. These professional RC
hell pilots are incredible.

------
gchokov
[https://www.youtube.com/watch?v=sa-
TSNeTK-A](https://www.youtube.com/watch?v=sa-TSNeTK-A) this one goes to 440mph
..

pretty impressive toys. How do you control this thing without FPV?

~~~
alan_cx
Possibly easier than piloting the real thing. No g-force, total vision, simple
controls, and so on. With various fail-safes and controllers, its made much
easier

Dont get me wrong, I've tried flying normal RC planes, and Im rubbish at it,
it is still hard and skillfull. But, if you spend some time on YouTube looking
at what people can do with these things, you'll end up wondering if they are
bending physics.

~~~
TheSpiceIsLife
I taught myself to fly RC planes using RealFlight[1] RC model simulator using
the same transmitter / controller I used for the RC planes configured with
progressive rate controls connected via USB interface.

10 hours on the sim using a high-wing trainer with lots of dihedral[2],
learned how to land in a gusty cross wind, then out in to the park with my
high-wing high-dihedral trainer. Took off, flew, and landed no problems - the
RealFlight trainer was nearly spot on.

I then bought a model F4U Corsair, much different plane to fly, they go where
you point them and don't self right or self level like a high-wing high-
dihedral aircraft. More RealFlight training and then flew and landed it
successfully first go to.

Lots of fun! The parks I had easy access to weren't in suburbia though.

1\. [http://www.realflight.com/](http://www.realflight.com/) 2\.
[http://en.wikipedia.org/wiki/Dihedral_(aeronautics)](http://en.wikipedia.org/wiki/Dihedral_\(aeronautics\))

~~~
gchokov
Hey! Thanks for sharing these!

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fpvracing
Anyone into this kind of thing may like to check out FPV racing:
[https://news.ycombinator.com/item?id=8510680](https://news.ycombinator.com/item?id=8510680)

Not quite as fast, but just as much fun!

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konstruktor
That's a turbine powered RC plane, and, technically, an unmanned aerial
vehicle, but it doesn't seem to fly autonomously.

~~~
danieldyer
Exactly. It's just a radio-controlled model aircraft, which have been around
for a long time.

Also, it's worth pointing out that it's not a model of a fighter jet, and that
this video seems to be a repost of one that's been up for five years:
[https://www.youtube.com/watch?v=dTHWBSluUjU](https://www.youtube.com/watch?v=dTHWBSluUjU)

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spikels
Wow - just realized how slow most drones are.

Could something that small break the sound barrier?

~~~
danieldyer
Only if it were rocket powered. The aerodynamics simply don't scale well
enough for something that small to become supersonic using any currently
available small turbine engine.

~~~
termain
What part doesn't scale? The only thing I can think of that might be a problem
is the boundary layer thickness through the intake/diffuser.

~~~
danieldyer
Roughly speaking, the drag is proportional to cross-sectional area, whereas
engine thrust required is proportional to mass, which in turn is proportional
to volume. So, you end up running into a square-cube law situation:
[http://en.wikipedia.org/wiki/Square-
cube_law](http://en.wikipedia.org/wiki/Square-cube_law)

Also, the Reynolds number will be completely different for a model aircraft
compared to a full-sized aircraft, so they will behave quite differently
aerodynamically.

It's also worth pointing out that even the fastest full-size jet aircraft can
only just break the sound barrier at sea level (the F-111 did Mach 1.2 at sea
level) – going supersonic typically requires flying at a high altitude, which
obviously isn't practical or legal for a radio-controlled model aircraft.

~~~
termain
>Also, the Reynolds number will be completely different for a model aircraft
compared to a full-sized aircraft, so they will behave quite differently
aerodynamically.

For low speeds, maybe. For high speeds, you're well into the high Reynolds
number turbulent regime. I've worked on R/C aircraft designs and I'm
reasonably sure we got decent results with inviscid aerodynamics. At sea
level, you're going to see Re in the millions.

Regarding the Square-Cube law, I'm not sure it's that relevant here. It's
pretty clear you could put two of those engines in a AMA sized model, so not
exceeding 55 lbf. That'd give you a thrust-to-weight ratio of greater than
1.0.

~~~
danieldyer
> Regarding the Square-Cube law, I'm not sure it's that relevant here. It's
> pretty clear you could put two of those engines in a AMA sized model, so not
> exceeding 55 lbf. That'd give you a thrust-to-weight ratio of greater than
> 1.0.

Yes, a small turbine-powered RC aircraft can easily have a higher thrust-to-
weight ratio than a full-sized aircraft, but it's not thrust-to-weight ratio
that determines top speed; it's thrust-to-drag ratio.

This is where the square-cube law comes into it. If we take a full-sized
delta-winged high performance aircraft like the Eurofighter Typhoon, we could
very roughly approximate the difference in drag between that and the model to
be proportional to the difference between the square of their wingspans.

I'm guessing the aircraft in the video has a wingspan of 1 m, and the Typhoon
has a wingspan of 11 m, so the drag should be greater by something like a
factor of 121.

However, the Typhoon's engines provide a combined 180 kN of thrust, which is
greater than the 160 N thrust of the Jetcat P160 by a factor of 1125.

So, you can see that the thrust-to-drag ratio of a full-sized jet fighter is
something like an order of magnitude larger than for a model aircraft like
this, which is the main reason why model aircraft are unable to attain
supersonic speeds.

Of course, supersonic flight for model aircraft would pose all the same
problems it poses for full-sized aircraft; onset of compressibility affecting
control surface response, engine inlet geometry and so on.

~~~
termain
>Yes, a small turbine-powered RC aircraft can easily have a higher thrust-to-
weight ratio than a full-sized aircraft, but it's not thrust-to-weight ratio
that determines top speed; it's thrust-to-drag ratio.

And parasitic drag dominates, right? Ok, so yeah, I was thinking in terms of
induced drag. Thanks for the discussion. I enjoyed it and it was a good
refresher.

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spyder
Another one with 4 jet engine and onboard camera:
[http://www.youtube.com/watch?v=ZeL3LhrmeME](http://www.youtube.com/watch?v=ZeL3LhrmeME)

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scotthtaylor
Amazing, would love to see this advance to have a camera capable of relaying a
camera feed to an Oculus Rift.

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owenversteeg
The engine is
[http://www.jetcatusa.com/p160.html](http://www.jetcatusa.com/p160.html). Only
costs $4200, which is not too far out there in comparison to quad/hexa/octo
setups.

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rdlecler1
Super cool, and I can't imagine how you could fly this. This is going to scare
the hell out of the FAA and Homeland Security. I expect the FBI will start
paying the turbine company a visit.

~~~
ceejayoz
These have been around for many years. The FAA already regulates them.

[http://en.wikipedia.org/wiki/Radio-
controlled_aircraft#Jets](http://en.wikipedia.org/wiki/Radio-
controlled_aircraft#Jets)

> In the U.S.A. the FAA heavily regulates flying of such aircraft to only
> approved AMA Academy of Model Aeronautics sites, in where certified turbine
> pilots may fly. Also, the AMA requires model aviation enthusiasts who wish
> to operate miniature gas turbine powered RC model aircraft, to be certified
> in the operation of the type of gas turbine engine, and all aspects of
> safety in operating such a turbine-powered model aircraft, that they need to
> know in flying their model.

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jokoon
that's old

I still wonder what are the best tech available to have a camera/screen on
this thing, with what latency.

~~~
bigiain
So far as I can tell _nobody_ flies FPV (first person view) with anything
except regular analog video cameras and radios.

I'm guessing that's at least partly for cost reasons, but mainly because you
don't even need to ask the "what latency" question. Even though
iPads/cellphones/OcculusRift have much better and higher resolution screens
than most of the inexpensive hobby FPV gear around, the lag as you
digitise/compress/decode real time video streams is both too long and too
variable.

Remember John Carmak's rant about being able to get packets to London quicker
than he can get them onto his screen? Imagine trying to control a ~400mph toy
plane when you aren't sure if you've got 15 or 200ms of latency at any time?
That'd represent "seeing where you are" something between ~10 and 200 feet
behind where the plane is right now.

~~~
stephenitis
Thanks for referencing the John Carmak "rant". I missed this. anyone else
interested. [http://superuser.com/questions/419070/transatlantic-ping-
fas...](http://superuser.com/questions/419070/transatlantic-ping-faster-than-
sending-a-pixel-to-the-screen)

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jpeg_hero
we need more women in the uav industry.

good careers to be had here.

