I totally agree with this analysis. I used to push in the first one or two seconds to help keep the trolley going. I am not sure that is needed in the first place, but what it led to was me forgetting to pull in and having sketchy launches. Once I became aware of this issue and fixed it by pulling in properly, my launches were pretty much all perfect: no unwanted roll, no slingshot out of the trolley and a smoother transition to flight. I think the tug was also accelerating more nicely. And I never worried about being pulled over either. (chest only on an intermediate glider).
So many factors to consider… initial nose angle set … quality of the wheels to roll properly… field conditions-grass height and rolling drag- cross winds ..etc. I personally like to start off with body aft. for first few feet of roll then relax me back pressure and plum forward to allow the tail to rise just as you rightfully put it.
The key to lifting the trolley is having enough speed-and thus lift-to ensure a successful start. However, it can go wrong if the pilot raises the AoA without first building sufficient speed. Done correctly, the trolley lifts no more than 15 cm, which is acceptable. Alternatively, the same goal can be achieved by teaching a different technique that avoids lifting the trolley altogether. But I think lifting it a bit is a good technique how to check if there is anought AIRspeed and lift.
I noticed the Atos with the good launch had 15 to 20 degrees of flap whereas the bad launch appears to have zero flap, this has an effect on the speed at which the wing lifts.
Good analysis. To the pilot that was hangs with the elbows high and the feet low because it's more comfortably for them, I'd say: Sounds great. Set yourself up like that after you have released!
It's funny, but even before the bad launch, I was totally put off by the bad body position of the pilot. Definitely hang flat, if you'd like to have more control! Nice video! 😃
Good discussion Pete. The comment that hit home for me was when you described the Atos on the "T" trolley as starting in a stalled condition. Now, given that the Atos keel is designed at -5 deg wrt the wing's chord, and the keel of the Atos in the "T" trolley looks to be at about 25-30 deg wrt to the ground (and therefore airflow whilst on the trolley), the Atos wing is seeing an initial angle of attack of 30-35 deg: i.e. deeply stalled. If the Atos pilot just hangs vertically during the initial roll-out he is effectively keeping it in that stalled state 🤔 With a flex-wing the keel is at a definite +ve angle wrt the chord so the wing is probably not held in a deep stall on the trolley??
@alanhughes51 I did measure Steve's ATOS (VR?) on both of our trolleys. I can't remember the actual numbers but it wasn't quite as much as you are saying. But yes, I agree with your analysis that a Flex will be unstalled at a much lower keel angle than a rigid. And on the flex, when we come out the keel will often hit the stand proving that the wing flies just fine at that angle. A lot of the ATOS launches I watch at MAC, the keel doesn't really lift before lift off. I will bring my inclinometer the next time we get out and we can get some more real-life numbers.
I totally agree with you, weight needs to be slightly forward and body flat. Body flat will make it easier to get weight forward and maintain position. Great video.
As far as I can judge the keel holder of the trolley is in the same height for both the flex wing and the rigid wing. I don't know a lot about aerotow launches, I have never done it by myself but as far as I know the keel holder of the trolley has to be in a higher position for the rigid wing. This is because of the fact that an Atos has a smaller angle between the wing and the keel in comparison to a flex wing (especially a single surface glider that builds up a pronounced tunnel). In a higher position you don't start with a stalled wing as it happened here und you don't have to pull in that much to compensate the low keel holder position. Just my opinion, free for discussion, as I said I don't know much about towing ;-)
This article discusses the difference between flex and rigid wings. With the same angle of attack (airflow relative to wing) you have different keel angles between the glider classes (see picture on page 54). So it looks much more "nose up" when you see a single surface glider start or fly and I think this has to be considered when setting up the trolley. www.dhv.de/media/jahre/2024/02_fliegen/Lehrmaterial/Artikel/Flugtechnik/Haengegleiter/249_Sicher_starten_mit_dem_Drachen.pdf
Damn, I didn't even know you could start with something like that! And when I asked hang glider pilots, they told me that you have to live in the mountains to be able to fly it. Is this a common method?
@@Zbigniew_Nowak it is becoming a more and more common way of flying HG. It means you need a club and a tow plane. But no exhausting climbs up hills and you get to rig and de-rig by your car. Aerotowing is a real luxury! But there is a buzz to flying off hills as well. I wouldn't want to only have one method. Where do you live? There might be an aerotow club near you...
@@petermontgomery6498 In Poland, so I'll probably find such a club sooner than you know ;) What about towing behind a fast car or a device that winds a rope onto a spool? This seems cheaper than a towing plane.
@Zbigniew_Nowak yes there are various methods of surface towing. Static winch, truck towing, step towing. There will be a club in your area. Look them up and ask for advice on how you can join in!
@@petermontgomery6498 Only money, money! :) But you know what, when I have more money and join there, I will tell them about this possibility of taking off a hang glider, if they don't know it yet. ;)
NOT A FLYER (well 20-30 hill runs in 77). Seems to me that you would want to pull DOWN to move your legs up by rotating at your pivot point of the harness. It doesn't look like just pulling forward would do this. Could it be more natural to pull down because it would seem that that would pull you forward also?
@@mnice59 head down-toes up or head up-toes down doesn't change your CofG relative to the glider at all so doesn't make any control inputs. Being head down is uncomfortable but gives you more ability to control the glider.
Was not the bad takeoff a bi- product of that dolly design? Because he was hanging that upright in his harness, the pilot had to have his feet on either side of that dolly- designs keel (even worse if he pulled in) .
@@kimp8079 yes but being that upright was the cause not a "bad trolley". Here is another one of my videos using that trolley. No issues. ruclips.net/video/xeqDQxCqHsA/видео.htmlsi=5gol6CM7cDmzjiI4
@@petermontgomery6498 Hi ! Yes. But I do not think being that upright is a problem in the dolly which has the "V" design. I have done, as my memory serves me, maybe two dolly- launches, so not an expert on that😅, but plentiful of static line foot launches, and I like to hang a little bit upright in the harness on tow...just for comfort. Better breef the pilots about their feet on that "T"- dolly ? Anything wrong with the short brief: Hang flat enough, Pull somewhat for speed and let the dolly almost lift, or lift a little, before letting go ?
@kimp8079 if you are too upright in the V design trolley you hit your feet on the rear of the two front bars as you come out. That is why this pilot actually prefers this T trolley!
Everyone praises their own horse. In your analysis, you did not take into account the fact that the footage shows three different aircraft with different stall speeds. The first is the Atos VQ, a mid-range wing that starts at around 32 km/h, depending on the pilot's weight, the second is the Atos VR wing, a competition kite that starts at just over 36 km/h, and the third wing that you praise so excessively is the most easily controllable wing for beginners, forgiving of all mistakes and starting at 25 km/h. 🤣🤣🤣
You are missing the point. It is irrelevant what the stall speed of any one type of hang glider is. The principle is what is important here and it follows through regardless of how they differ relatively. Just because one has a higher stall speed (and the DHV claim the VQ and VR have the same min speed by the way) doesn’t make it ‘trickier’. It just changes the RELATIVE speeds at which each stage happens. But that is the whole message of my video. FLY the machine. If one machine takes a longer ground roll because it needs more airspeed before it is safe to lift off, that doesn’t make it harder or more dangerous! And FYI - the real risk with the single surface gliders is how slowly they produce lift meaning that if you do not get the tail up they can seriously roll in the cart. I have a couple of bits of footage of exactly this, one on a Falcon and one on an intermediate but could not use it in this video because I did not have the permission of the pilots to use them. You can have just as clean and safe a trolley launch on a really tricky to aerotow glider as you can on a really easy to aerotow glider. But even those distinctions are subjective. Many pilots say that the ATOS is easier to aerotow than any flexwing. Certainly in my club we have had people who struggled with flex so they switch to rigid and have no issues. But like I say, this relative difference is irrelevant. The need to fly the glider through launch is the same regardless.
![Noob To Max With DRAGON REWORK In Blox Fruits [FULL MOVIE]](http://i.ytimg.com/vi/LnBMOinoOvA/mqdefault.jpg)
I totally agree with this analysis. I used to push in the first one or two seconds to help keep the trolley going. I am not sure that is needed in the first place, but what it led to was me forgetting to pull in and having sketchy launches. Once I became aware of this issue and fixed it by pulling in properly, my launches were pretty much all perfect: no unwanted roll, no slingshot out of the trolley and a smoother transition to flight. I think the tug was also accelerating more nicely. And I never worried about being pulled over either. (chest only on an intermediate glider).
So many factors to consider… initial nose angle set … quality of the wheels to roll properly… field conditions-grass height and rolling drag- cross winds ..etc. I personally like to start off with body aft. for first few feet of roll then relax me back pressure and plum forward to allow the tail to rise just as you rightfully put it.
The key to lifting the trolley is having enough speed-and thus lift-to ensure a successful start. However, it can go wrong if the pilot raises the AoA without first building sufficient speed.
Done correctly, the trolley lifts no more than 15 cm, which is acceptable.
Alternatively, the same goal can be achieved by teaching a different technique that avoids lifting the trolley altogether. But I think lifting it a bit is a good technique how to check if there is anought AIRspeed and lift.
good analysis Pete !
I noticed the Atos with the good launch had 15 to 20 degrees of flap whereas the bad launch appears to have zero flap, this has an effect on the speed at which the wing lifts.
Great video - thank you!
Good analysis. To the pilot that was hangs with the elbows high and the feet low because it's more comfortably for them, I'd say: Sounds great. Set yourself up like that after you have released!
It's funny, but even before the bad launch, I was totally put off by the bad body position of the pilot. Definitely hang flat, if you'd like to have more control!
Nice video! 😃
Good discussion Pete. The comment that hit home for me was when you described the Atos on the "T" trolley as starting in a stalled condition. Now, given that the Atos keel is designed at -5 deg wrt the wing's chord, and the keel of the Atos in the "T" trolley looks to be at about 25-30 deg wrt to the ground (and therefore airflow whilst on the trolley), the Atos wing is seeing an initial angle of attack of 30-35 deg: i.e. deeply stalled. If the Atos pilot just hangs vertically during the initial roll-out he is effectively keeping it in that stalled state 🤔
With a flex-wing the keel is at a definite +ve angle wrt the chord so the wing is probably not held in a deep stall on the trolley??
@alanhughes51 I did measure Steve's ATOS (VR?) on both of our trolleys. I can't remember the actual numbers but it wasn't quite as much as you are saying. But yes, I agree with your analysis that a Flex will be unstalled at a much lower keel angle than a rigid. And on the flex, when we come out the keel will often hit the stand proving that the wing flies just fine at that angle. A lot of the ATOS launches I watch at MAC, the keel doesn't really lift before lift off. I will bring my inclinometer the next time we get out and we can get some more real-life numbers.
I totally agree with you, weight needs to be slightly forward and body flat. Body flat will make it easier to get weight forward and maintain position. Great video.
As far as I can judge the keel holder of the trolley is in the same height for both the flex wing and the rigid wing. I don't know a lot about aerotow launches, I have never done it by myself but as far as I know the keel holder of the trolley has to be in a higher position for the rigid wing. This is because of the fact that an Atos has a smaller angle between the wing and the keel in comparison to a flex wing (especially a single surface glider that builds up a pronounced tunnel). In a higher position you don't start with a stalled wing as it happened here und you don't have to pull in that much to compensate the low keel holder position. Just my opinion, free for discussion, as I said I don't know much about towing ;-)
This article discusses the difference between flex and rigid wings. With the same angle of attack (airflow relative to wing) you have different keel angles between the glider classes (see picture on page 54). So it looks much more "nose up" when you see a single surface glider start or fly and I think this has to be considered when setting up the trolley.
www.dhv.de/media/jahre/2024/02_fliegen/Lehrmaterial/Artikel/Flugtechnik/Haengegleiter/249_Sicher_starten_mit_dem_Drachen.pdf
Damn, I didn't even know you could start with something like that! And when I asked hang glider pilots, they told me that you have to live in the mountains to be able to fly it. Is this a common method?
@@Zbigniew_Nowak it is becoming a more and more common way of flying HG. It means you need a club and a tow plane. But no exhausting climbs up hills and you get to rig and de-rig by your car. Aerotowing is a real luxury! But there is a buzz to flying off hills as well. I wouldn't want to only have one method. Where do you live? There might be an aerotow club near you...
@@petermontgomery6498 In Poland, so I'll probably find such a club sooner than you know ;) What about towing behind a fast car or a device that winds a rope onto a spool? This seems cheaper than a towing plane.
@Zbigniew_Nowak yes there are various methods of surface towing. Static winch, truck towing, step towing. There will be a club in your area. Look them up and ask for advice on how you can join in!
@@petermontgomery6498 Only money, money! :) But you know what, when I have more money and join there, I will tell them about this possibility of taking off a hang glider, if they don't know it yet. ;)
NOT A FLYER (well 20-30 hill runs in 77). Seems to me that you would want to pull DOWN to move your legs up by rotating at your pivot point of the harness. It doesn't look like just pulling forward would do this. Could it be more natural to pull down because it would seem that that would pull you forward also?
@@mnice59 head down-toes up or head up-toes down doesn't change your CofG relative to the glider at all so doesn't make any control inputs. Being head down is uncomfortable but gives you more ability to control the glider.
Was not the bad takeoff a bi- product of that dolly design? Because he was hanging that upright in his harness, the pilot had to have his feet on either side of that dolly- designs keel (even worse if he pulled in) .
@@kimp8079 yes but being that upright was the cause not a "bad trolley". Here is another one of my videos using that trolley. No issues. ruclips.net/video/xeqDQxCqHsA/видео.htmlsi=5gol6CM7cDmzjiI4
@@petermontgomery6498 Hi ! Yes. But I do not think being that upright is a problem in the dolly which has the "V" design. I have done, as my memory serves me, maybe two dolly- launches, so not an expert on that😅, but plentiful of static line foot launches, and I like to hang a little bit upright in the harness on tow...just for comfort. Better breef the pilots about their feet on that "T"- dolly ?
Anything wrong with the short brief: Hang flat enough, Pull somewhat for speed and let the dolly almost lift, or lift a little, before letting go ?
@kimp8079 if you are too upright in the V design trolley you hit your feet on the rear of the two front bars as you come out. That is why this pilot actually prefers this T trolley!
Everyone praises their own horse. In your analysis, you did not take into account the fact that the footage shows three different aircraft with different stall speeds. The first is the Atos VQ, a mid-range wing that starts at around 32 km/h, depending on the pilot's weight, the second is the Atos VR wing, a competition kite that starts at just over 36 km/h, and the third wing that you praise so excessively is the most easily controllable wing for beginners, forgiving of all mistakes and starting at 25 km/h. 🤣🤣🤣
You are missing the point. It is irrelevant what the stall speed of any one type of hang glider is. The principle is what is important here and it follows through regardless of how they differ relatively. Just because one has a higher stall speed (and the DHV claim the VQ and VR have the same min speed by the way) doesn’t make it ‘trickier’. It just changes the RELATIVE speeds at which each stage happens. But that is the whole message of my video. FLY the machine. If one machine takes a longer ground roll because it needs more airspeed before it is safe to lift off, that doesn’t make it harder or more dangerous! And FYI - the real risk with the single surface gliders is how slowly they produce lift meaning that if you do not get the tail up they can seriously roll in the cart. I have a couple of bits of footage of exactly this, one on a Falcon and one on an intermediate but could not use it in this video because I did not have the permission of the pilots to use them. You can have just as clean and safe a trolley launch on a really tricky to aerotow glider as you can on a really easy to aerotow glider. But even those distinctions are subjective. Many pilots say that the ATOS is easier to aerotow than any flexwing. Certainly in my club we have had people who struggled with flex so they switch to rigid and have no issues. But like I say, this relative difference is irrelevant. The need to fly the glider through launch is the same regardless.
That is a VQ Race. Same min speed as VR anyway.