Bob27

The pilot was probably laughing and saying to his co-pilot, "Watch this, it's going to be really funny!" Anyway, I'm glad your okay. I think there is a good lesson here for everyone including helicopter pilots to learn.

Is may be true for a standard car mechanic, but I believe it would be far less true for an aircraft mechanics as they often must repair things rather than replacing them. For example if a wing rib is damaged he would most likely fix it but in doing so he must fully understand the structural loads and take this into account with how he would repair and reinforce the wing rib. Also due to the diversity in construction methods and design almost no repair would be the same. He may not have the skills or knowledge of designing an airplane but he has a pretty darn good idea of the strength of materials and what a properly designed structure looks like. He is also a civil engineer. He basically specializes in knowing how strong materials are and and how they will react under loads. Is this really any worse than a hydraulics engineer for analyzing how a solid metal structure will crumple?

Sorry, A&P license. Or Airfame and powerplant license. It basically means that he is a certified airplane and helicopter mechanic.

On the other hand a good friend of mine has an AMP license and is a civil engineer. I believe he loves the flat top design more than anyone else. I would love to see test results published along with dummy crash testing.

sorry, air bag.

Yes.

I can totally respect what you have said. I may have a slightly different view on crumple zones because of all the people I have spoken with who have personally used them in paragliding and paramotor accidents, but at the same time I agree with you that they don't work in all situations.

I believe I understand reflex wings perfectly well. Let's go through exactly how they work because it sounds like many people here don't fully understand. First thing you need to understand is that a paraglider wing operates with a ram air intake which is strategically placed to take in air from the location where air pressure is highest. This means that the air pressure inside of a paraglider is higher than anywhere else on the wing. This allows for a paraglider wing to be more than a fancy bed sheet and it allows a paraglider wing to take almost any shape that the designer wants. So what designers discovered is that the internal pressure in a well built wing is high enough that they could curve the rear of a wing upwards enough to to point where the trailing edge would create a slight down force. What this does is it makes it so that you can place the cg a farther forward. This makes it so that as your speed increases, the angle of attack increases and your speed decreases, the angle of attack decreases. It also allows reflex wings to maintain a proper angle of attack in relation to the wacky air currents in turbulence which is why they are more stable than non-reflex wings. So this is true for non- reflex wings and wings not in reflex mode, but it is not true for reflex wings in reflex mode. Reflex wings in full reflex mode and with full speed bar, the A lines very tight with 50-75% of the load and the B lines fairly tight with the remaining load. All the remaining lines shouldn't have any load. If a reflex wing did rely on on those 2 unbalanced lines to maintain stability, everyone who has ever tried reflex would be dead. Also watch this video. It shows how reflex wings are not reliant on the wight distributed below the. It also proves my point that there are some pretty major changes the the airfoil shape to make a reflex wing do what it does. So this is not completely true. If the entire purpose of the reflex wing was to unload the back half of a wing, you would die because of your lack of stability. If you don't believe me take a non reflex line and cut the c and d lines during flight. If I am right, you would fall out of the sky.(please don't actually do this as you would fall out of the sky.) So yes a reflex wing will increase the loading closer to the leading edge, but the back half of the wing is still regulating the angle of attack and regulating the angle of atack to make up for the C and D lines being slack. Also a reflex airfoil is still an airfoil just like a non reflex airfoil. So aerodynamically the aspect ratio doesn't really change.

Basically the entire reason we use a reflex airfoil on an tailless flying wing for it's stability. The disadvantages of it are that it produces more drat and less lift. So if you put 2 back to back the non-reflex would fall out of the sky. Now there are a few tailless aircraft that I have built where I haven't needed reflex wings due to an insane amount of sweep back and that probably my most efficient glider.

I am referring to the power difference required to flying with large amounts of speed bar in full reflex mode. In this mode some high speed 16 square meter reflex wings are hitting sometimes over 55mph, but they need close to full power to maintain elevation. On the other hand people with 16 square meter non-reflex wings are hitting maybe only 35-40mph, but with the right wing they can do that at nearly half throttle. It will also vary a lot with wings. Not all wings are created equal. I have personally built many reflex winged rc airplanes because reflex airfoils do have there advantages, but efficiency is not one of them.

Sorry, I am very experienced with 2 stroke engines and am more familiar with using standard profile wings than more modern and high performance paramotor wings. So maybe I should re-visit everything that I have said. Reflex wings are far less efficient and faster than standard profile wings, so for XC you need to hold medium to high power for long periods of time, not medium to low power like you would with the standard profile wings which are slower and more efficient. So yes, a lower compression to increase the engines XC capabilities is completely reasonable.

If only that could be the standard... Maybe someone should make a way of scientifically testing everything from engine performance, wing performance, frame safety and performance and make it all uniform testing that it concreate so we can finally see through to what is truly the best and what is just trash.

You can alter a power curve on a 2 stroke engine by changing the shape of a cylinder head. Basically a deeper cylinder head will provide more low end power and a flatter cylinder head will provide more top end power. Changes in compression will often change things differently in different engines, but in most cases with small 2 stroke engines, lower compression will give more top end power and high compression gives better bottom end power. There are a lot of little reasons for this and it will sound counter intuitive to many people out there, but its often how it works. So my guess is that the tornado xc cylinder head has a more narrow and slightly taller combustion chamber with a higher compression ratio to increase the efficiency in the mid power range.

I agree with you. I do believe the dominator is a good EN-A wing but there is no way it could keep up with most comparable sized reflex wings especially in long distance xc flights. I have talked to Dell a few times and he is honestly one of the most fun person I have ever talked with. I have also learned that he truly believes every word that he says. Now with that In mind, I don't think he fully understands every concept behind how a reflex works which I think has made him more more apposed to it, but he has flown dozens of reflex wings him self. I found this interesting interview that someone not affiliated with him did. I don't think it will make you change your mind on everything he has ever said, but it shows a slightly different side of him and it helps show people who have never met him that he does believe what he says. It is interesting listening to around the 40ish minute mark when he talks about his own gear and other gear. It goes to show that he is not as against reflex as many of his videos demonstrate and he isn't really apposed to people flying wings other than his own dominator. On a different topic I have had this on my mind for a bit so here is my little rant on a theoretically possible paramotor wing that could possibly be better than reflex: I once saw a wing where you could zip up or fold up the two center cells of the wing while on the ground to effectively take it from something like a large to a medium size. Its called the U-turn paramotion if anyone wants to look it up. With that in mind, I think that someone needs to take a non-reflex wing and design the center third of the cells to collapse in an accordion style while in flight. this would effectively cut the wing area in nearly half and reduce the aspect ratio from around 5:1 down to around 3.3:1. Theoretically if you could do this properly, you could keep up with any comparable size reflex wing, out climb with ease any wing in reflex mode, maintain active piloting at all speeds, be able to use regular brakes for better control, and the wing would recover from collapses almost as fast, but far more gently preventing other problems. Also because you are not loosing the efficiency of a reflex airfoil, it would be appealing to paraglider pilots. Of course the technical challenges would make this extremally difficult, but It would be really cool.

I'm really hoping that there is a proper resonating camber within the exhaust. If not, you will loose a bit of power.

Yup, I'm sure Dell would sign up on paramotor club just to say the the sky tap is "one of the best on the market." Lol. But seriously. I think if Dell could put any paramotor manufacturer out of business it would be sky tap because it is taking a ton of his costumers from him and it is a clear copy of his design.

View Advert Radne Racket engine Only comes with engine, prop, throttle, fuel line, and mounts. Good condition with great compression. More power and less weight than an atom 80. Asking $1350 OBO. Advertiser Bob27 Date 07/10/20 Price Category Other  

I'm confused. You guys bash me for saying the dominator is a decent wing and I get bashed for proving that the flat top 120 is close to it's advertised weight, but none of that comes close to how much I get bashed for saying that the sky tap is one of the best paramotors on the market. I thought that people were buying sky taps to avoid getting bashed...

I have met all of Dells 4 kids but his oldest daughter. I have also met Trevor. I don't know Dell and his wife have done it, but he has raised some of the most down to earth and incredible kids I have ever met. I must say that sky tap looks pretty slick in all black! If that is your sky tap in the picture, how do you like the anti torque lamels? I have been interested in those, but have seen some mixed reviews on how effective they are. Also would you happen to fly the Cima power? I have been interested in that wing for a while but I have yet to actually find someone other than Andrew who flies them that I could talk to. Like every paramotor on the market, I do struggle with a few key points in the sky taps design, but I do believe that you have one of the best paramotors on the market.

No. The lightest model would be a flat top 120 with a Radne Racket engine. That one is claimed to weigh 47 pounds. The 200cc Minari f1 and the classic vittorazi moster 185 engines are supposedly within an ounce of each other so with those engines the flat top is claimed to weigh 56 pounds. You can watch videos done by people like PPG grandpa who is a critic of the flat top. Anyway he weighed the frame without the engine, throttle, or fuel tank and it came out to be 24.3 pounds. (It did have a thrust plate) I have personally weighed some of the individual pieces to a flat top frame and that seems perfectly reasonable. I have also weighed an entire Radne Racket engine optimized for the flat top with the thrust plate, all hardware for mounting to frame, throttle, fuel line, fuel bulb and filter, intake baffle, and everything else. It came out to be 22 pounds. Add the weight of the engine and frame and you have 46.3 pounds. Add one pound for the prop and replace the weight of the thrust plate with a fuel tank and you have a 47.3 pound flat top 120. That is 0.3 pounds more than what Dell says it is. The only numbers there that we do not know for certain is the weight of the thrust plate and designated hardware which was weighed with the frame and the weight of the fuel tank which wasn't weighed with the frame. Basically I know that the flat top 120 is within a minimum of 1.5 pounds of what flat top paramotors advertises and likely much closer, so I would think their other units would be pretty close to accurate.

In my opinion what needs fixed is the harness which makes it feel so heavy.

Weight is honestly not terrible. At 56 pounds with a vittorazi moster or Minari f1 it weighs less than the carbon scout with a moster plus. If you want to see a really heavy paramotor, look at The fresh breeze monster. That thing weighs 71 pounds!

I disagree on the flat top part. Dell really liked the walkerjet paramotor and didn't like when the switched frame designs. So he worked in collaboration with one other guy to design the flat top which was heavily based off the walkerjet. The flat top has evolved over time. For example, Dell had the comfort bars widened for better weight shifting ability. He also changed to a smaller gauge of aluminum that makes up a portion of the crumple zone. I believe it because a guy crashed and broke his back basically because a lot of things went wrong and the crumple zone wasn't soft enough. I'm not saying that the flat top is perfect by any means, I can list off a bunch of stuff that I would like to see changed which could improve performance, comfort, safety, and ease of use.

I know more than most people do about reflex, I wrote a long article about reflex where I go into depth on exactly how it works and the pros and cons of it. It is on the Facebook group called "paramotor master chat" if you want to look it up. It's actually Dells Facebook group and I sort of said a lot of things contradictory to what he has previously said about reflex, so I hope it is still there... Yes the Dominator is a 10 year old wing without reflex. There have been some "updates" such as light weight fabric on all the wings and racing lines on to the XXS and smaller wings which does greatly improve performance, but it has been questioned as to how it impacts the longevity. If you want to see some unbias reviews, Mark Honeycutt does a decent first impression review on it. You can also go look up a bunch of other people who have tried it and the majority of them have good things to say about it.

This is my view on the Dominator/K2 wing. The wing was originally designed for hike and fly. Because it was designed for that in mind it has a high lift coefficient(more lift for the same size of wing so that you can pack a smaller wing up the mountain) So when you are flying a large 28m dominator like sharf3007 it won't feel sporty at all, but when you fly a XXS 19m or smaller Dominator with nearly 135kg weight at over 5000' elevation like Dell, it can be a pretty darn sporty wing. These are my current thoughts on the wing. There are safer wings on the market, and there are faster and better performing wings on the market, but I think that the Dominator/K2 has one of the best performance to safety ratios of any wing on the market. If you truly can not stand Dell you could also look into Cima power. It is the exact same wing and it has been designed by the exact same person. The only difference is that it has been optimized for paramotor use and it has some modern technologies implemented.