Cooled gas turbine transition duct

A transition duct for a gas turbine engine incorporating a combination of cooling structures that provide active cooling in selected regions of the duct while avoiding cooling of highly stressed regions of the duct. In one embodiment, a panel formed as part of the transition duct includes some subsurface cooling holes that extend under a central portion of a stiffening rib attached to the panel and some subsurface cooling holes that have a truncated length so as to avoid extending under a rib end. Effusion cooling holes used to cool a side subpanel of the panel may have a distribution that reduces to zero approaching a double bend region of the panel. An upstream subpanel of the panel may be actively cooled only when the panel is located on an extrados of the transition duct.