I've created a section on "High Lift Devices" on my web site (non-commercial and free) at http://homepage.mac.com/mikejames/rc...ite/index.html which includes info on flaps of different kinds, slats, spolers, leading edge devices, etc.. It includes various contributions from other RCU participants, so check it out.

By the way...
After I read Andy Lennon's book ("The Basics of RC Model Aircraft Design" ( http://www.rcstore.com/rs/general/li...id=8&catego=BO ) and tried his approach, it was proven to me that many of the pitching issues associated with flaps can be solved by increasing their chord to 30%. Of course, like on an actual aircraft, flaps shouldn't typically be deployed at high speed. If you wait until you've slowed down a bit for your landing approach, then apply the flaps, you'll have much less pitch up on deployment.

Anyway, flaps and all the other gadgets are fun, and can be challenging to build, if you choose a scale method. I think they add a lot to both the looks and performance of a model.

Happy flying!