ineffective yaw control typical for this type of helicopter. They didn't show an autorotation as this is where you'll see a reversal in yaw authority - See QH 50 Gyrodyne for this cure in yaw control issues
هذه المروحيات بشفرات تدور عكسيا هي الأفضل في التوازن في الجو حتى عند هبوب الرياح القوية إذن فهي الأنسب والأكثر ملائمة لعمليات الانقاض حين الفياضانات وغيرها من الكوارث
We think the price is quite good compared to competitors which ask for 200k and more. Right, they mostly have two seats and there are also cheaper single seaters than us. But we offer a complete built and certified helicopter. Ready to fly.
No we stopped the test after we reached a lifetime of 2000 hours in this dynamical test. We carried out an additional structural test with a load factor of over 3 for centrifugal forces. Additionally, we damaged the blade with over 10 holes with a power drill. It didn't break in structural test, too.
I like all the folks asking about price. They apparently don't know about helicopters, or aircraft in general. If you have to ask the price, you cannot afford one! The cost to enter is very high (but fair for the complexity) and once you are "in the door" the cost to maintain must be taken into serious consideration. Lots of moving parts that need constant inspection and sometimes replacement. I guess it is a case of be rich or go home, but their price seems fair.
How do you perform dynamic balance of the rotors? I know how to perform it on a single rotor machine, but how do you separate the vibrations from each rotor?
Blades are balanced as you do on a single rotor helicopter. The lower and upper swashplates are connected with pushrods. Each blade can be adjusted, what means that those pushrods are not loaded very much because both rotors run very smooth after adjustment and therefore also not much vibration.
@@RS-fr1je I understand how the tracking could be achieved. However if there is slight in balance in one rotor say one blade is slightly heavier than the other or the center of mass is not exactly the same on both blades, an imbalance occurs with a resulting vibration. If the normal single rotor balancing is done, an accelerometer is used to measure the amount of vibration and there is an optical device employed to determine at what point or angle of the rotation does the accelerometer read its max. This is fine except which rotor is causing the vibration? Also this must be done in a hover to avoid the affect of the vibrations reflecting from the ground. On a single rotor ship that has the engine turning the same rpm as the the tail rotor, it is difficult to isolate vibrations coming from the engine vs the tail rotor. The dual rotors must exacerbate that problem?
@@stufields5125 We have the advantage to manufacture our own blades. They are made out of carbon fibre and are manufactured in a solid autoclave mold. So the outer geometry is always the same which leads to the fact, that there are no differences in aerodynamical behaviour between two rotor blades. As you already wrote, vibrations can occur due to differences in the whole blade mass or the centre of gravity. Now we have two directions of the centre of gravity: longitudinal relating to the blade length or lateral (blade width). Lateral tuning is done by measuring this c.o.g. and aligning the main fixation bolt exactly onto this line. But there's only a small range where this is acceptable. The c.o.g. should be at the same lateral position as the centre of aerodynamic forces in order not to flutter or to create unnecessary loads in the control system. The inner blade setup with additional weights is designed to reach that range and this is working quite good. If it's outside that range, the whole blade goes into the garbage. The longitudinal c.o.g. can be adjusted by small additional weights at the end of the blade, which also leads to a different total weight. The blade pairs of our helicopters are selected in pairs which fit best to each other at all design parameters in order to reduce vibration. So we don't manufacture 2 bades and say: "They will be attached to the next helicopter. If they don't fit to each other, we will tune them with additional weights." It's more that we manufacture 10 or 20 blades and select the best pairs before fine tuning is done.
@@RS-fr1je I found that to truly check dynamic balance on my Safari, I had to perform an measurement while hovering. This is done after a static balance check is performed and the blades aligned to eliminate any lead/lag and a tracking test and adjustment is done. My balance checks would involve hovering the ship with the accelerometer mounted close to the mast and pointed inward. An optical sensor was used to detect the angular position of the mast and rotor when the accelerometer reading peaked. This would tell me the angular position where the "Bad" wt was and I would use the plan "Add Opposite" to add wt to the rotor system at a point opposite the "Bad" wt. I would typically try to first add wt to the nearest blade tip and the repeat the test and find a reading of the chord wise balance. I was able to get total vibration less than 0.05 ips in three starts. This was of course after I determined gram wt vs ips. You sound like you are manufacturing a quality blade which should certainly reduce the dynamic vibration. That said how about the 2/rev vibration normally associated with a single rotor in forward flight? It has to be there but whether it gets to the pilot's butt is another question.
Looks like à good machine! But have you planed creating some derived version for the other countries? In France, the ultralight needs to have a MTOW < 500kg. In fact, can't you just limiting administrativement a new version at 500?
Thanks for your comment. For other countries we will also try to certificate the VA250. To limit the weight to 500kg would be the easiest possibility I guess.
@@elouanlavaux1514 For VA115 we have about 100€ per hour including nearly everything (insurance, inspection, spare parts, fuel,... but no buying price). For VA250 we don't expect much more. Let's say an estimated operating cost of 125€ per hour.
By changing the angle of attack of the upper rotor blades and therefore reducing or increasing their drag while the lower rotor plane remains as it is.
@@user-eu8ij8io5y Yes that was a test, especially fixed on the ground. And no, the blades are not too small ;) We have experience in calculation and design due to our certified single seat helicopter VA115. The VA250 will have the same good flight characteristics :) But we still need to carry out some ground tests before flying. It's not a Rotax engine.
@@user-eu8ij8io5y Thank you very much :) We use the Hirth F23 for our single seater VA115. The VA250 has another one but may change in future. Therefore for the time being, we don't say which type ;) We still need to carry out some structural and ground tests in order start flight testing. I think in summer you can see it flying :)
Isnt this supposed to go under the new eu ultralight weight category? Dont they have a simplified framework for certification? Wasnt that the point of the whole thing? Why is this priced like a regular helicopter at 150k? It doesnt look like its supposed to cost that much. Theres a swedish company producing a manned coaxial quadCopter under the same regulation that will be charging 60k euro for it. The stylish fraundorfer tensor is under similar simplified regulation and will cost 1/10th the price of this. Its a gyrocopter so simpler mechanics but otherwise comparable and were talking 10% the price of this. Even though coaxial rotor might be more complex doesnt the lack of tail rotor make the whole production process and maintenance a great deal more simplified? So what then is up with the astronomical prices for machines that doesnt look that more complex than a kawasaki? I get that they cant be as affordable as a sportsbike but come on, can you place the pricing somewhere around that area. Even half the price would be almost acceptable but 150k for a new rotorcraft under UL weight category is just grotesque
I don't know it fits EU regulations. We will certify it for German ultralight heliopter specifications. After that, we'll try to get more certifications in different countries. EU regulations may be the same or similar. And yes, probably the framework for certiication is simplified but it's still a helicopter. Please show me regular helicopter at that price (new ones). I won't give detailed numbers of our costs and I won't compare to quadcopters or gyrocopters, but in order to understand the "high" price, you can make yourself a small overview. Just look at some aviation shops and sum up the prices for avionics and radio system. You'll get some thousand € only for this. Then an engine, a lot of machined parts, quite huge composite parts (which are handmade), aviation grade bolts and a lot of other standard parts, such as bearings. Quite all sports bikes are manufactured at a large-scale series production. You can't compare their costs to a relatively small series aviation production. Most of our assemblies are handmade which takes time and time is money.
It is a free market...you can set whatever price you want if there is demand you are going to sell...Sometimes you have to pay extra just for availability...I do not know any other Coaxial helicopter at this price range...so there is no competition. Furthermore to get to production scale and quantity is a huge investment of capital and time/resources...I congratulate RS for their effort!
A quad copter or alike VTOL has different aerodynamics and advantages/disadvantages in each use case scenarios from helicopters...their limitations in weather are also different...For certain applications the new VTOL/eVTOL designs will not replace helicopters for other areas they are going to disrupt the market...
Is it really not possible to make new rotorcrafts more affordable? 150k euro is just way out of reach for the common man. In terms of machinery is this really that more advanced and complex than a modern sportsbike that can be had brand new for 20k euros? Even with the maintenance and certificationa that drive up the price is 150k really where its at?
150k is an estimated price because we still haven't finished the certification of the whole helicopter. After that, we'll get more detailed numbers. But please also consider, that flying in general isn't the common hobby of the common man. Additionally, helicopters may be the most expensive way of flying. I think 150k are quite low compared to other helicopters.
