A gas turbine engine augmentor includes an annular trapped vortex cavity pilot having a cavity forward wall, a cavity radially outer wall, and a cavity aft wall, an annular cavity therebetween, and cavity fuel injector tubes operably disposed through the outer wall into the cavity. Circumferentially spaced apart radial flameholders with integral spraybars and/or radial spraybars interdigitated with the radial flameholders radially inwardly into an exhaust flowpath of the augmentor just forward and upstream of the trapped vortex cavity pilot at a radially outer portion of a combustion zone of the exhaust flowpath. An annular trapped dual vortex cavity pilot version is operable for producing trapped dual counter-rotating inner and outer vortices of fuel and air mixtures.