I have just been elected the district 4 JPO rep and live in the northern MD area. We have a few clubs that allow turbines planes. Looking near DC is hard but as the guys have stated the DCRC and FreeState clubs are two that do. Also PGRC and SWAP are the nearest clubs to DC that allow and encourage turbine flying. The Pegaus RC club in Hagerstown has a few guys as well. We allow turbines to fly at our field so long as e can pass the DB limit. I have flown my smaller powered planes there several times but prefer rallies.