Ok, I have a slight problem with a vignette I would like to build.
The vignette that I am building is of a couple of friends playing with an RC plane and not sure how to work it.
The figures are in 1/20th scale but unfortunately I am not really sure what scale the plane needs to be to represent an RC aircraft.
I have no idea when it comes to this subject what plane,much less what scale to use that would work well with my 1/20th figures.
So please if anyone who can help me in this dilemma,I would be very happy.
Thank you.

You can get away with any 1/144 WW II fighter in that scale. It would approach a 'giant scale" kit in proportion to your figures. One of these perhaps. (try and ignore the more than slightly skeevy cartoon figures; the models are little gems)

Interesting dilemma. I guess that depending on the type of aircraft that they are "playing" with and the scale of that aircraft, you might consider using a 1/700 or 1/350 naval scale aircraft. It would probably look just about right for a large R/C aircraft.

The Sweet Aviation Models 1/144 scale planes are very nice, but they would be huge next to a 1/20 scale figure.

Jim

They can easily get that big

1:144 would be 1:7 scale for your figures, that is a big model.
A P-51 mustang, for example would have an 6 foot wingspan in your figures' world.
If you want a smaller model, something like 1:10, or 1:14 scale - this would make for a model the figure could be shown holding - you want 1:200 or 1:285 scale (popular war games scale) in our world. I think you should take a look at Shapeways
https://www.shapeways.com/marketplace/miniatures/aircraft

how about this 1:285 Cessna 172, its wingspan of 1.52 inches would be 30 inches in your figures's hands.

something like this