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CHALLENGE: Variable Geometry Wings


Hostage Taker of Quads

Interesting challenge -- So are you proposing building a model of an existing aircraft, or playing with variable geometry in new and different ways?
It is worth noting that swept wings are only needed at high airspeeds, and even the world record holding gliders -- approaching 500 MPH -- still use completely straight wings. The use of variable geometry wings would only be used for scale effect. It is at this point worth noting that just about every commercial jet with variable geometry wings has gone *way* over budget.

The one area where variable geometry wings are used to great advantage are rocket launched gliders The wings are tucked tightly against the fuselage during launch and then deploy at apogee. The most well known example is the Estes Scissor Wing Transport:

I am currently in the early design stage of a larger, radio-controlled version of this model, but I am a total newb so I'd really love to see what the FT guys can come up with here.


Junior Member

Interesting challenge -- So are you proposing building a model of an existing aircraft, or playing with variable geometry in new and different ways?
I'd like to see an all out scratch build with the usual materials. It can be based on an existing aircraft, but it shouldn't be an exact copy. It should also be said that the wings must sweep mid flight and the plane must still retain good handling characteristics. This would probably mean a very fast plane with wings fully swept.
Excellent idea for a challenge! Something I bet David would jump all over sorta like the Viggen. The catch for me is this.....Flitetest for the most part has stuck with challenges that are accessible to the average scratch builder (Turkeyflyer aside lol). Something scalable that anyone with a couple sheets of foam and some hot glue could try to tackle. Getting variable geometry to work on the build table I image would be entirely different from getting it to work in the air with repeatable positive outcomes. Any pivot system would have to be fairly robust even for a parkflyer, perhaps not cnc custom fabricated aluminum parts as seen on the Tomcat in vid but definitely beyond foamboard, tape and popsicle sticks. I would love to see it done on Flitetest either way and who knows wing pivots as seen in large scale military craft are not the only means by which to change geometry mid flight. I wouldn't put it past the FT team to come up with some relatively simplistic approach that just about anyone could attempt.
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I just saw that plans were posted for this very cool model....
As I read over this thread I was picturing a servo driven hinge system like what that SU22 uses. I think the real drive would be to get a model built that had the true benefits of a variable geometry wing and less just getting one to fly. Like something that would perform like a funjet with the wings swept and then soar with slow speed stability with them open wider.
Lift capacity formula

I am fairly new to RC and around the intermediate level. I'm building the FT simple storch and am curious as to how to figure out the payload of a particular plane.