Building a HIGH SPEED Rocket Plane

In this video you'll see what happened when I took an RC SR71 Blackbird and upgraded it to see how fast I could make it fly. I installed new engines, improved its aerodynamics, and fitted a powerful solid

rocket

booster that could be activated in mid-air. I've been challenging myself to build faster and faster

rocket

plane

s here at Project Air for a couple of years and now I'm slowly increasing their

speed

s with each new project, solving problems along the way and doing my best to catch them up without running out. completely destroyed in the process. The

plane

would be quite different as it would be the first to use a new type of rocket engine with a super long burn time, so the plan was to take a very standard RC jet and modify it to fly as fast as possible online. straight.

Using battery power alone, the second stage would be to increase this top

speed

by activating a rocket motor in the air, which would cause the plane to accelerate to an even faster top speed. It seems appropriate that we use the SR71 for one of these speed airplane projects as the Blackbird was one of the fastest airplanes ever created, the problem is that this foam RC model is not really designed for

high

speeds, so maybe We could change it and make it more like the real thing, first we needed to find out exactly how slow the plane was.

For starters, which meant taking it out of the box and assembling it for its first test flight, the plane came with two very small 40mm ducted electric fans that propel the plane through the air using power from the onboard LiPo battery to pitch and roll the plane, the plane was equipped with four microl linear servos, but these seemed a little flimsy, they would hold up when we started to increase our airspeed, for now it was time to head to our normal flying field and put this . thing in the air as the creators intended for some reason.

I get a warning on my transmitter, but it's in the sky, getting closer. Well it's working, it doesn't seem particularly fast right now, look at that, it looks so cool, come on. Full throttle now and do a low pass, that was pretty quick right? So we only have a couple of minutes of battery left, so I'll try to make the most of it. Oh, okay, I think that's revealing. I say it wants to land, so let's bring it in, see how fast the plane went at 108 km per hour, that is 60 MPH. I think so, let's see if we can improve this plane in the workshop.

Okay, there are some very easy things. We can do to this plane to make it faster and it is important to make it as fast as possible before adding rocket engines to make sure we are really optimizing the top speed of this plane. Now it's one of the easiest mods I can do. do with this airplane is eliminate these codes on the front of the engine, the cells, we just want to get as much air into the duct fans as possible and right now these are restricting the next key thing I needed boarding was streamlining the plane.

I absolutely needed to record the flight from onboard to analyze what the plane was doing in the air, but the camera I was using was massively increasing the frontal area and overall drag of the otherwise quite slippery. I decided to switch and use a much smaller insta 360 go3 camera instead of the big bulky camera. With the new camera installed, we now had a much more optimized setup for capturing onboard video while making these initial modifications. I also tried some new Spectrum batteries to see if we could get more power out of these ducted fans, it turned out that these new batteries made a big difference, which could also be heard now.

I was excited to see how these upgrades would affect the Blackburn's top speed. There, so that's working, this is definitely recording, yeah. stop read 150 that's much faster look at that 150 we had increased our top speed by a decent 27% but now I wanted to push the plane over 100 mph on battery power alone which would be much more difficult due to the problem of the increasing drag at

high

er speeds, air resistance actually works in a bit of a strange way, drag increases as an object moves faster through the air and collides with more and more air molecules exerting a force opposite.

As our SR71 increases its speed, it will hit more of these molecules. With more Force, in theory, if we want to fly twice as fast, we would need four times as much power, which is quite a difficult task. We had already depleted battery power, so now is the best way to squeeze more oomph from the electrical systems. would be to improve the blackbird's fans through this rudimentary smoke test. I could visibly see the volume of air sucked in by the ductive electric fans. I was also able to see the speed of the air coming out of the exhausts and it was really interesting to see that there was actually not that much air moving here, the original fans were quite small so increasing the size of the fan would allow us to draw in more air and get him out from behind faster.

I found some new larger fans that were reused from one of my floor effects. The fan cards projects and after a quick service they were almost like new. I was now able to remove the old engines from the SR71, which required a bit of surgery on the aircraft, and then I was able to connect the new fans directly to the internal flight computer to see if they would work, it wasn't entirely straightforward, although I found I had to remove quite a bit of foam from the intake and also had to add nose weight to correct the balance of the plane, which would add to our total flying weight.

It became a problem. So would fans move more air? There was a very obvious difference. A lot more air was being drawn into the primary intake and secondary vents and seemed to be blown out the exhaust. faster, this was a big step towards our stage one goal of getting this aircraft over 100mph on electric power alone. The problem was that I now made the plane much heavier, so it would still fly. It has some power. Oh oh dear, I think we're okay. After adjusting the elevator trim, I can trust the flight computer to keep the plane level and try again with that hair-raising takeoff out of the way.

I finally got the plane flying and accelerated hard doing an alignment. I was able to do a couple of sprints. before having to land yes 163 we had finally reached 101 MPH meaning stage one of the project was complete now we could turn our attention to stage two and start experimenting with some rocket boosters, a solid rocket motor operates according to a combustion principle. solid propellant the rocket motor casing contains a mixture of solid propellant composed of fuel and oxidizer when ignited, the solid propellant undergoes rapid combustion producing hot gases that shoot out of the nozzle generating a thrust force in the opposite direction now What is going to be different?

The relationship between this rocket plane and other rocket planes I have built in the past has to do with these rocket engines. These small-sized rocket motors burn for much longer than the ones I've used before they release their energy much more slowly, allowing the vehicle to accelerate. more smoothly, this rocket plane here used a much more violent engine and barely survived the fire 3 2 1. If it were to use a much more gradual engine to accelerate slowly, then maybe it would be easier to fly with this and also easier to survive . the plane I wanted to test the rocket engines and collect data before attaching them to the beautiful SR71 Blackbird.

For this I would use a data logger seen in previous videos on my channel that can be used to measure thrust, like that of these rubber giants. The band motors used in my rubber band plane video, this load cell and the data logger would all have to be mounted on something and we initially thought about 3D printing a plastic base but that might not have been the best idea since we were going to try. with Rocket Motors that run a little hot, so we realized we needed to make our metal test bench, but instead of making it ourselves, we machined this part by PCB, who are actually sponsoring this video after waiting for for the pieces to arrive.

Unpack them and quickly assemble the finished test bench, complete with electronics to measure the thrust of the rocket motors. I'll press this one, it'll go D and then it'll start fine, so we're here with the load cell. We're going to do our first rocket motor tests, we've got Emma here who designed the load cell, so yeah, we're going to fire it. Now we tested three identical motors and the data showed that we get around 100 Newtons on average. Push through a 7 to 8 second burn, so yeah, pretty good, big thanks to PCB Way for sending all the parts for this rocket engine test bench.

It has been really very useful. All you have to do is design a few parts in CAD and then upload them. Take them to the website and you can send them to be made. It's really simple and there are a ton of great tools to make things in different ways, so be sure to check out the PCB form with the link in the description. Many thanks to them for sponsoring this video, okay, now I have tested rocket engines on the ground. I can start working on mounting them on the RC plane as our speeds increased. In fact, I found it quite difficult to keep track of the stealthy black plane in the sky when I was controlling it, so my solution was to paint this plane a special color, as you may have noticed, the previous rocket planes on my channel were mostly orange, however, I wanted to try something a little different with this particular plane and paint it.

It's gold because I thought it might be a good opportunity to see if the shine of gold and its reflective nature could make it even easier to see the orientation of planes. Now, with gold paint, the unique-looking Blackbird could be reassembled complete with the project's air markings. and of course my patreon names as a thank you for signing up for my patreon you can sign up with a link in the description to add your name to my future builds now to make quantities for the engine using a cardboard tube now to make this rocket plane Working electronically I discovered that I would have to make some important changes.

Remember that the flight computer from before turned out to not really be very customizable, which meant you would have to switch to a new radio system. This actually wasn't a problem. The downside was that it gave me the opportunity to upgrade the radio system to one with much more redundancy and better range. The problem was that with this bulky receiver there was simply no room on this aircraft to fit a gyroscope like the one built into the flight computer. This was now going to be a fully analog experience requiring you to fly the plane with all the flying skills you had with the new control systems finally all connected, new stronger Sur installed and the powerful fans running at 100% again. the igniter circuit a courtship test with that the plane was all finished and ready for what this video has been leading up to the rocket's first power test flight to see what these long bird motors transmitter power would do in controlling seal hatch check igniter direction LED circuit snap test igniter camera circuit start recording check that it's okay so we have the plane here now we are at the Flying Field um and we have the rocket engines that we are going to use in this proof.

We have the 8 second ignition, this engine will run for 8 seconds and give us, you know, a good solid boost of about a kilogram, you know, constant thrust, there's very little chance of success with all this, you know, it could all go very wrong. . Very quickly, the flight pattern is to take off into the wind, do a loop, and then hopefully, if everything looks good, if we haven't crashed at that point, we'll get the green light and fire up the rocket. Let's see what happens, okay? let's turn around okay, we have a green light okay and then 3 2 1 jump and shoot correctly trying to get your bearings the gold paint is working fine we're down we're down I think we're in the lost fields Oh boy, that was so out of control, it was so hard to keep it straight without the gyroscope, right.

I'm going to go try to find it with the Scout drone. I think luckily we're only a couple of fields away. it's gold so it'll be pretty easy to see that's what he found it found it we found it so we successfully burned it uh the plane didn't crash on takeoff uh there's a lot of positives, I'm not sure how fast we went so that is whatLet's go find out now let's see how fast it was with the GPS, see? where did it go it was here oh there it's okay it's like in one piece it's kind of dug into the ground look this is stuck tight oh my god it's actually stuck I can't actually get it out I can't actually get this out of the ground, oh there we go, so the big question: how fast was it?

Okay, so stop reading 200 km per hour 200 km per hour exactly look at that, that's sp, that's pretty impressive right, let's see how damaged the plane is in the shop and then we can see if it will ever fly again , so we tried to fly the plane again, but unfortunately I had more problems with the manual launch and unfortunately we couldn't get the plane back into the sky. The plane was too unstable and ridiculously difficult to keep level. I had to run a lot to get the right air. speed and yes, it was almost impossible. I kept damaging the plane and we had to go back to the shop and go back to the field and yes, unfortunately in one of these tests or in one of these attempts the plane crashed into the ground and was written off instantly, so this plane is pretty much destined for the Air Museum project now, but it is, yes, we have definitely learned a lot from it, for a long time, but the rocket engines I will use on the next plane, well, actually, if you look at the pictures of the test flightIt looks like the plane It ran out of room while I was still accelerating, so I had to stop and lose speed in a turn and that meant the plane basically wiped out some of its potential at the speed it could have.

It would be gone if this was using all its fuel in a fraction of the time, so I think I'll go back to more violent, shorter-burning rocket engines in the future. We put it in the air that time and we did it. a pretty impressive top speed of 124 mph, we actually doubled the top speed of the original plane or more or less it was, I think, 10 mph, so we've learned a lot from this part of my rocket plane program and probably in the next video. We will start working on a new type of rocket-powered aircraft, although it will be very different, so if you want to see it, be sure to subscribe to be notified and also watch another video in the meantime.

I'm waiting for the next video on Project Air to come out. I think you will like this one too, so click on the next one. Thank you very much for watching this video and see you in the next one.