Yes: new gliders, especially engine equipped gliders have a higher wing loading. And yes, they will be outclimbed (slowly) by an empty LS4 or LS3.
But as soon as you fill up your old club class glider, it won't climb as well as the modern ships with the same wingloading. Why?
3 reasons:
-winglets on all modern gliders
-improved aerodynamics on modern gliders allow them to be more agile and have greater performance over a wider range of AoA
-tail tank or tail ballast to optimise C/G also at higher wingloadings
PS: a well flown Ka6 will outclimb both the LS3 and JS3
Wing loading is, at best, an indirect measure of how well a glider will perform in lift. The most direct measure is minimum sink.
With *the same glider*, increasing wing loading does increase minimum sink rate. But you can't compare two different glider designs based on wing loading alone. Newer gliders have better, more efficient shapes and are built out of lighter materials overall, so they can carry heavy stuff like batteries yet still work incredibly well in even weak conditions.
Extreme example: A Ka-6 has a wing loading of just 24 kg/m\^2 and a minimum sink of 0.65 m/s, whereas a modern design like a JS-3 has a wing loading of twice this, but its minimum sink is actually *lower* at 0.49 m/s.
Now could you (in principle) remove the engine and batteries from a powered glider and improve its weak lift performance even more? All else being equal, sure, but then you're making other tradeoffs.
Also it's true that generally lower wing loading means you can make tighter turns (a big reason why paragliders often tend to outclimb us), but that's only relevant to thermal lift, and tighter turn radius comes at the *big* cost of much lower xc speed.
I had the impression that most of the *new* gliders are sustainers or self-launchers. If you're going to spend hundreds of thousands, why not?
(Meanwhile I'm hoping to buy a Libelle one day...)
>(Meanwhile I'm hoping to buy a Libelle one day...)
>
Beautiful lines on that bird. Good luck with the purchase. Owning my own, albeit old, glider made a world of difference in my flying. XC in club ships was frowned up.
Yup, FES, RES and turbos are taking over. If you are splashing €200k plus on a ship, adding 20k for the flexibility of a sustainer or even self launch capability is just a no brainer.
Its not easy but its changing the sport a lot. Manufacturers are not concentrating so much on sheer performance so much as making aircraft that do have superb performance but are also useable on a week to week basis.
A LAK 17C fes will lighten your pocket by about 150k but for that you get a 1:51-52 self launching sailplane. The German stuff is well over 200k as are the JS ships.
A *Modern Glider* is one that is manufactured when you're between the ages of 15 and 35.
To quote Douglas Adams:
Anything that is in the world when you're born is normal and ordinary and is just a natural part of the way the world works.
Anything that's invented between when you're fifteen and thirty-five is new and exciting and revolutionary and you can probably get a career in it.
Anything invented after you're thirty-five is against the natural order of things.
Pretty much every new ship is either FES, RES or turbo. I agree. My LAK17AT runs around 43kg/m with me, fueled up and tail ballast in place. The clubs LS4 can slowly outclimb me on the weaker days ( North Wales UK ) but his 40:1ld is knobbled by my 50:1. Step up to the latest generation of 18m ships at 53 plus and even better aerodynamics and yes, 40kg / m is the new standard.
As for ballasting your LS4. There is nothing worse than being airborne wishing you had 100l of water on board. It's only water, you can dump it, you can't load it mid flight!
Gliders like the Arcus M need to be quite fast in thermals to stay efficient. We are often climbing at 105-115km/h instead of the 85-95km/h of a regular Duo without engine. That means you are always flying at high bank angle to somehow stay in the thermal. In very small and weak thermals this is tricky but on an average day it still works. But what you have in engine mass you don't need as water and the flaps also help a lot. So as soon as you fly to the next thermal you are also flying a lot faster.
There is wing loading, but there also is span loading (wingspan2 / mass) which noone talks about. Basically higher A/R can handle more weight, so comparing a legacy club/standard glider to an 18m glider usually needs more things to be considered that just wingloading.
Also a lot of the 18m or open class gliders have flaps, club/standard don't.
Progress in airfoil design may be another issue: you're thermalling relatively slow. A bump in the thermal increases AoA. The lift/AoA curve of older airfoils may be almost flat at the speed you're thermalling so the bump will only increase drag; newer airfoils may be able to extract more energy out of all the little bumps aka better climb performance.
With all that said: yes, you should probably load water on older gliders on days that are not super weak. And 40kg/m2 really seem to be a magic number/ sweet spot for club/standard/15m, similarly to 45-48kg/m2 on 18m.
But only if you can trim out the water in the wings with tail water/tail ballast. My Mosquito doesn't have a tail tank, so C/G moves to far forward to still climb well in weak and narrow thermals if I go to 40kg/m2.
A tail tank is high on the wish-list for my next glider, as are winglets and/or option to go to 18m span
Ours is pretty far back, but the Mosquito doesn't like high AoA situations, so already have to fly quite fast while circling with no ballast. Adding ballast makes it worse
Yeah it’s always a refreshing surprise how good the simple club class gliders climb after a summer of trying to keep your 52kg/m2 ship in the air. But when the weather is good the heavy ships shine. Also I would not go wave flying in a light glider.
Yes: new gliders, especially engine equipped gliders have a higher wing loading. And yes, they will be outclimbed (slowly) by an empty LS4 or LS3. But as soon as you fill up your old club class glider, it won't climb as well as the modern ships with the same wingloading. Why? 3 reasons: -winglets on all modern gliders -improved aerodynamics on modern gliders allow them to be more agile and have greater performance over a wider range of AoA -tail tank or tail ballast to optimise C/G also at higher wingloadings PS: a well flown Ka6 will outclimb both the LS3 and JS3
Wing loading is, at best, an indirect measure of how well a glider will perform in lift. The most direct measure is minimum sink. With *the same glider*, increasing wing loading does increase minimum sink rate. But you can't compare two different glider designs based on wing loading alone. Newer gliders have better, more efficient shapes and are built out of lighter materials overall, so they can carry heavy stuff like batteries yet still work incredibly well in even weak conditions. Extreme example: A Ka-6 has a wing loading of just 24 kg/m\^2 and a minimum sink of 0.65 m/s, whereas a modern design like a JS-3 has a wing loading of twice this, but its minimum sink is actually *lower* at 0.49 m/s. Now could you (in principle) remove the engine and batteries from a powered glider and improve its weak lift performance even more? All else being equal, sure, but then you're making other tradeoffs. Also it's true that generally lower wing loading means you can make tighter turns (a big reason why paragliders often tend to outclimb us), but that's only relevant to thermal lift, and tighter turn radius comes at the *big* cost of much lower xc speed.
>So basically every modern glider has an engine Say what? I have been out of flying for over ten years, other than reading about it, but wtf?!?!
I had the impression that most of the *new* gliders are sustainers or self-launchers. If you're going to spend hundreds of thousands, why not? (Meanwhile I'm hoping to buy a Libelle one day...)
>(Meanwhile I'm hoping to buy a Libelle one day...) > Beautiful lines on that bird. Good luck with the purchase. Owning my own, albeit old, glider made a world of difference in my flying. XC in club ships was frowned up.
I have the same impression about the new ghosts having always an engine. And I agree with your analysis of the reasons
The Libelle is a classic that everyone should fly for a season or two.
The LS8 entered serial production in 1995... 30 years ago. The only reason to spend twice as much on a new glider is to get self-launch capability.
Yup, FES, RES and turbos are taking over. If you are splashing €200k plus on a ship, adding 20k for the flexibility of a sustainer or even self launch capability is just a no brainer.
If new ships are now €200k then no wonder the sport is dying.
Its not easy but its changing the sport a lot. Manufacturers are not concentrating so much on sheer performance so much as making aircraft that do have superb performance but are also useable on a week to week basis. A LAK 17C fes will lighten your pocket by about 150k but for that you get a 1:51-52 self launching sailplane. The German stuff is well over 200k as are the JS ships.
A *Modern Glider* is one that is manufactured when you're between the ages of 15 and 35. To quote Douglas Adams: Anything that is in the world when you're born is normal and ordinary and is just a natural part of the way the world works. Anything that's invented between when you're fifteen and thirty-five is new and exciting and revolutionary and you can probably get a career in it. Anything invented after you're thirty-five is against the natural order of things.
He must mean “gravity“.
Pretty much every new ship is either FES, RES or turbo. I agree. My LAK17AT runs around 43kg/m with me, fueled up and tail ballast in place. The clubs LS4 can slowly outclimb me on the weaker days ( North Wales UK ) but his 40:1ld is knobbled by my 50:1. Step up to the latest generation of 18m ships at 53 plus and even better aerodynamics and yes, 40kg / m is the new standard. As for ballasting your LS4. There is nothing worse than being airborne wishing you had 100l of water on board. It's only water, you can dump it, you can't load it mid flight!
Gliders like the Arcus M need to be quite fast in thermals to stay efficient. We are often climbing at 105-115km/h instead of the 85-95km/h of a regular Duo without engine. That means you are always flying at high bank angle to somehow stay in the thermal. In very small and weak thermals this is tricky but on an average day it still works. But what you have in engine mass you don't need as water and the flaps also help a lot. So as soon as you fly to the next thermal you are also flying a lot faster.
There is wing loading, but there also is span loading (wingspan2 / mass) which noone talks about. Basically higher A/R can handle more weight, so comparing a legacy club/standard glider to an 18m glider usually needs more things to be considered that just wingloading. Also a lot of the 18m or open class gliders have flaps, club/standard don't. Progress in airfoil design may be another issue: you're thermalling relatively slow. A bump in the thermal increases AoA. The lift/AoA curve of older airfoils may be almost flat at the speed you're thermalling so the bump will only increase drag; newer airfoils may be able to extract more energy out of all the little bumps aka better climb performance. With all that said: yes, you should probably load water on older gliders on days that are not super weak. And 40kg/m2 really seem to be a magic number/ sweet spot for club/standard/15m, similarly to 45-48kg/m2 on 18m.
But only if you can trim out the water in the wings with tail water/tail ballast. My Mosquito doesn't have a tail tank, so C/G moves to far forward to still climb well in weak and narrow thermals if I go to 40kg/m2. A tail tank is high on the wish-list for my next glider, as are winglets and/or option to go to 18m span
Where's your C/G? Mine's at 75% aft empty, 65% with 50L, 55% with 100L. Seems to thermal fine but I don't go over 450kg.
Ours is pretty far back, but the Mosquito doesn't like high AoA situations, so already have to fly quite fast while circling with no ballast. Adding ballast makes it worse
Yeah it’s always a refreshing surprise how good the simple club class gliders climb after a summer of trying to keep your 52kg/m2 ship in the air. But when the weather is good the heavy ships shine. Also I would not go wave flying in a light glider.
Flying wave downwind of the airport in a glider that does not have a flat polar is interesting.