Hier het laatste nieuws uit Amerika omtrent the Next Big T-Bird :
T3
Rémy Catillon wil sofort bestellen. Gerda, pas op voor jullie budget !!!
The story behind the T3
Since more then 1 year we have been working on a new plane that would have it all The very good thermalcapacity which could be found in the Twister 2 combined with the very good glides like the zone and Edge. We had the opportunity to test a molded plane with the Zone 2 sections against the Twister 2 and the outcome was like we predikted. The zone had a good launch and a good glide but was not capable of following the Twister 2 in the licht thermals and had to bail out early everytime. Whatever was tried with CG changing and flapsettings it very clearly showed that the zone V2 suffered during turning. It doesn't seem to deliver enough lift to keep up. Same thing we already noticed during a windy wether contest early last season were a lot of ballast was required . The sinkspeed during turning seems to be a lot higher then the T2. It might be very good in very actifve air were everything goes up but in the average european circumstances thermals are mostly not that strong and when they are its mostly very windy which means ballast.
So we had to develope a new series of sections which could keep up with the T2 in light thermals and still has the good glide. Beside that it needed to be a vorgiving section . Flying to fast or to slow is inherent to modellflying since we don't have speedometers. So a section that can handle some piloterror will be a lot better then a section that just have some extremely good peaks in a sertan range but suffers in another.
To make a long story short. after about 400 hours we ended up with a wing with a rootsection that is only 5.98% thick but outglides the zone and the edge with more then just a little bit and still delivers the same CL max as the Twister 2 does. Launch should be just as good as the zone V2.Beside that the CL/CD polars are very smooth meaning the sections will be forgiving for pilot errors.We also took a good look at the Cp distribution to make sure the sections can handle the turbulence. Its still a litlebit more alive then the T2 but all in the green zone.
The rootshort became slightly bigger then average for 2 reasons. First the bigger wings showed better results in XFLR5 and second it needed to be bigger to fit the servo in with the right angle for RDS.
So the wing got 22.9 dm2 .With the fast section there would be less ballast required so launching should not be a problem.
Vertical.
For the Vertical we took a good look to some fighterjets. Fighterjets create a vortex at high angles of attack that delivers extra lift and stops the wings from stalling. Same thing is created in the vertical. The root sections is only 4% thick and is symetrical. 2cm above and below the fuse the sections becomes 5% thick is slightly cambered and has an washout of 0.5 degrees making sure that he section still sees the air with CL 0. The rootsection will stall before the rest of the vertical creating a vortex at high angles of attack that runs over the vertical creating extra lift. Even thoug the sections for this vertical are extremely thin and have very little drag the vertical seems to be extremely effective and the plane shows no signs of tailswing and launches very high.
Horizontal
For the horizontal we went back to a symetrical airfoil. We had this on the Twister 1 also and liked the startbehavior better then the T2. Upto 95% of the power i can give in a launch everything was ok but when i really pussed it all the T 2 liked to go flat for a short while before the preset kicked in. This became worse when flown with a very forward CG like i like to do in strong turbulence . Non of this behavior was ever noticed on the T1 with a symetrical airfoil. A symetrical airfoil also needs a slightly more forward CG wich mostly will help turning smoothly in turbulent circumstances especialy when a lot of flap is deployed. It was hang under the boom this time to make sure that its not the spring that gives in at full power launches.
The stab was choosen slightly bigger then usual. Bigger stabs give smoother flights and allow bigger CG changes . The profit to gain here is mostly a lot bigger then the disadvantage of the extra drag.
Fuselage,
The boom of the fuse is slightly thinner then the T2 but still very stiff . The wing is bedded a litle bit deeper into the fuse , both to minimize drag. The front part is still short (8 inches) and designed for the 4 cell 500mah nimh. The cabine gives space to also slightly bigger servo's like the DS281/285. For the elevator i wouldn't choose a D47 this time.
What to expect
So you can expect a plane that launches extremely high,thermals very well and has the most amazingglide.
It can fly with a lot les ballast then the T2 .
The big stab allows a very wide CG range which converts this plane from a top floater with a bit after CG to a highspeed far rangeing dinamic plane with a bit more forward CG stil with very good thermal ability..
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uppydogeyes: 