Internation Miniature Aerobatic Club. www.mini-iac.com IMAC replicated the full scale aerobatic airplanes A.K.A. Scale Aerobatics. Pattern is similar to IMAC in that they both fly set sequences but both are quite different in the way they are judged and the way the sequences are setup. 3D doesn't technically have anything to do with IMAC or Pattern, it's basically aerobatics in the stall condition to say the least.

-Kelly