Jet Dragon Project

This is incredible… what’s even more incredible is you did this basically all by yourself! Have you thought about maybe with some more publicity you could get more help/funding? 
 

I look forward to videos and fly sight data! 

11 hours ago, alfonso904 said:

This is incredible… what’s even more incredible is you did this basically all by yourself! Have you thought about maybe with some more publicity you could get more help/funding? 
 

 

I look forward to videos and fly sight data! 

Thank you.

Actually I preferred to do everything myself, it was more difficult but also more rewarding.

So far I made several successful flights, and they are getting better and better. Once I will feel they are good enough I will publish video and flysight. Presently I'm aiming to 8 minutes flight.

Results so far ...   6L of fuel consumed. I'm still learning how to fly it efficiently

jet_powered_ws.CSV

On 8/1/2023 at 1:52 AM, alfonso904 said:

This is incredible… what’s even more incredible is you did this basically all by yourself! Have you thought about maybe with some more publicity you could get more help/funding? 
 

 

I look forward to videos and fly sight data! 

I don't know about funding but there are many talented people in Israel who would come at problems with new perspectives. Engineering trained skydivers in particular.

On 8/7/2023 at 2:31 PM, Gideon Yampolsky said:

Results so far ...   6L of fuel consumed. I'm still learning how to fly it efficiently

jet_powered_ws.CSV 4.53 MB · 1 download

Congratulations on pulling this off!

May I ask what's the biggest challenge in maintaining constant horizontal speed? Did you have thrusters "On" at constant RPM all the time or was it impulse acceleration?

During the entire flight RPM was 97,000 which is turbines' maximum.
As you can see in Flysigh recording horizontal speed was not constant. This because I was experimenting with body position. When I increased pitch (i.e. tried to “fly up”) I lost some of horizontal speed but managed to achieve level flight and even climb up a little bit.
My conclusion after experiments is, that with engines thrust, the optimal flight characteristics are different than in the case of regular wingsuit. Optimal flight speed with ATC wingsuit is around 150 Km/h. But with engines I found that optimal speed is around 110 Km/h, in body position aiming to “fly up”.
I’m planning to experiment more in future. But prior to further flights I have to make significant changes in some of system components, which will take time.
Sadly saying Israel went through horrifying event 10 days ago, which drew us into an unexpected war. So currently we have completely different priorities.
 

1 hour ago, Gideon Yampolsky said:

During the entire flight RPM was 97,000 which is turbines' maximum.
As you can see in Flysigh recording horizontal speed was not constant. This because I was experimenting with body position. When I increased pitch (i.e. tried to “fly up”) I lost some of horizontal speed but managed to achieve level flight and even climb up a little bit.
My conclusion after experiments is, that with engines thrust, the optimal flight characteristics are different than in the case of regular wingsuit. Optimal flight speed with ATC wingsuit is around 150 Km/h. But with engines I found that optimal speed is around 110 Km/h, in body position aiming to “fly up”.
I’m planning to experiment more in future. But prior to further flights I have to make significant changes in some of system components, which will take time.
Sadly saying Israel went through horrifying event 10 days ago, which drew us into an unexpected war. So currently we have completely different priorities.
 

I hope everything goes well for you, family, friends and Israel.

1 hour ago, Phil1111 said:

I hope everything goes well for you, family, friends and Israel.

One of my friends, pilot who took me up for jet test jumps, was killed in terrorists attack 10 days ago. He is one of 1300 civilians which were murdered in one morning

1 minute ago, Gideon Yampolsky said:

One of my friends, pilot who took me up for jet test jumps, was killed in terrorists attack 10 days ago. He is one of 1300 civilians who were murdered in one morning

Please extend my condolences to his family.

From April to August 2023 I made 10 attempts of powered flight. Only four of them were successful – engines started and run until all fuel was consumed. In other six jumps engine start issues rendered the attempt unsuccessful. One of engines was slow to start, until my flight altitude become critically low. 
After three consecutive fails in August I decided to take a break and focus on problem's solution. First I discussed it with engines manufacturer. They indeed confirmed that engine takes significant time to start, and they have no means to make it shorter. Next I tried to feed the engines with more flammable fuel, hoping that higher flammability will make it start faster. I replaced diesel with Jet-A fuel, which has 30% benzine. I was perfectly aware that something so flammable in intimate proximity is very bad idea. But at least I had to know if it works. Fortunately it did not work. Engine's start time did not improve.

The best solution was to start engines prior to the jump, as in such case it doesn’t matters how much time it takes. But they cannot start in vertical position when I’m standing on the launching shelf. I therefore had to redesign the launching shelf.
 

So far I tested it with engines on the ground and without engines in flight. I still need to make several small modifications and practice jumps before jumping this new version with jets.

Nothing like chasing your dreams...thank you for sharing your amazing journey!!!

Happy landings, Rafael

11 hours ago, manchuso said:

Nothing like chasing your dreams...thank you for sharing your amazing journey!!!

Happy landings, Rafael

Thank you :-)

On 3/15/2024 at 2:41 AM, Gideon Yampolsky said:

Thank you :-)

So any more progress?  Have you jumped the jets with the "start before exit"?

6 hours ago, SethInMI said:

So any more progress?  Have you jumped the jets with the "start before exit"?

8 flight attempts since then. Half of them were successful. In other half were unable to start one of engines. Still researching why. It is not technical glitch. Apparently combination of lower air pressure at high altitude and my decision to use 100% diesel as fuel. I'm currently tuning the fuel mix to make it more suitable for jet engines to start at 9000 feet.
Concurrently I'm working with quadcopter pilot to start filming the flight in air. Still work in progress.

the "trapdoor shelf" is working well?  Did you build and design that yourself? Sounded like you did.  What is the return mechanism after you leave? A spring? 

46 minutes ago, SethInMI said:

the "trapdoor shelf" is working well?  Did you build and design that yourself? Sounded like you did.  What is the return mechanism after you leave? A spring? 

The automatic shelf is working well. Build by me. Return mechnism is based on servo motor with gear, a kind used in robotic arms.

pretty sweet.  Did you think about the "what if the motor doesn't work" case? It looked like the shelf had to come up for a good landing.

47 minutes ago, SethInMI said:

pretty sweet.  Did you think about the "what if the motor doesn't work" case? It looked like the shelf had to come up for a good landing.

If motor will not take the shelf up, pilot can pull it manually. If not, landing with shelf hanging would not be nice, but probably it would not be a crash. Since it is paraplane, pilot can bring it to nearly zero horizontal velocity by flaring the canopy, same as with our landings.

But the funny thing is that I’m no longer using it. Explanation:
In past I was reluctant to fall on the back with jets running. I built that automatic launching shelf with aim to drop me down straight on the belly. But it did not happen. Every time I found myself on the back right after the drop.
So I decided to accept it. I practiced uncontrolled fall out on the back from Skyvan, until I obtained a good habits to make quick and controlled transition. 
From there, automatic launching shelf was no longer required. I replaced it with smaller equivalent permanently mounted shelf. I kneel on it, engines facing outwards, start engines, and then flip myself backwards, like scuba divers from the boat. In two seconds I’m back on the belly. It works pretty well, so this issue is closed.