Do any OpenPPGers have any interest in making some open source plans for a 2-4 jet “jet pack”? They use two 80kg thrust engines from AMT Netherlands.
https://jetpackaviation.com/jetpacks/
I fly a ParaJet 185cc, gas fuel PPG, and free fly. Many friends in the NJ/NY area have the 4 rotor OpenPPG model.
the big problem with those is they have very bad flight times, they burn a ton of fuel, the engines are very expensive, and the engines aren’t reliable for practical use.
To put the fuel consumption in perspective running two Nike engines from AMT you will burn upwards of 1 gallon per minute which will give you about 5 minutes of flight time with the US legal limit of 5 gallons(assuming you can keep the top speed under 55 knots so it can qualify as an ultralight). Even with a thrust augmentation device that can increase thrust by 100%, you could only get about 10 minutes of flight with 5 gallons of kerosene.
As cost goes a single Nike engine from AMT is over $25,000 and you need at least 2… Also the turbines in this size range will typically need a rebuild every 25-75 hours which gets really expensive.
The final and possibly biggest challenge is the reliability. Unlike Paramotors, if your engine fails you will fall like a rock out of the sky. And to make it worse you have 2 engines on each side that aren’t known for their reliability and if either of them fails you could die.
It would be really cool someday but I don’t think our technology is there yet.
Thanks Bob!!
Typically people are flying these over water, because of the engine failure issue you mentioned. Of course water brings its own issues.
Or they are doing something more like gravity industries where they have more like 6 engines for redundancy.
Or you use that existing concept…
a friend of mine flew with 2 turbines jakodofski 24 kg 2008 ppg. the big problem with this … the turbines have a very high jet speed which brings little performance at 0 km / h. at 35 km / h much more. you can fly without any problems. but as soon as the air is unsteady as usual with the weather … it is like this: as soon as the wing rises due to an increasing air mass, the wing stands up a bit as usual. the engines push in. the pilot moves more forward than usual with ppg because he has less resistance due to the lack of a cage and propeller pressure surface. as soon as the wing nods forward again and accelerates, the engine pushes again. that means you have to be an absolute professional and constantly stabilize actively with the brakes as a safety measure or you just fly in absolutely calm air just before sunset. purely from the performance, it is so that around 10 liters of kerosene are used for a 10 minute flight. it is possible in principle. however, it requires a very high level of technical knowledge. because the turbines are sensitive, for example if they are too full during the start process, etc. the exhaust gas jet is also able to heat up and damage the lines within 1 sec. when you turn. Good special hearing protection is also important, as the turbines run in a noisy area that quickly causes hearing damage without being loud. Model builders know that when they do full throttle test runs on jets. a jetman reaches around 70 dBa 150 meters away. a ppg around 60 -65 dba an eppg when it is quiet around 50 dba.
Funny thing is that the video is made by the same gravity industries that I just referred to.