2026ApJ..1000..174R

We report milliarcsecond-scale VLBI detections of compact radio nuclei in four spiral-hosted double-lobed radio-loud AGNs (spiral DRAGNs), a rare class that challenges the traditional association of powerful jets with elliptical hosts. Using public VLBI data archives, we identify compact cores in all four sources and resolve parsec-scale jets in two of them. The VLBI components show low brightness temperatures (T_b ≈ 10⁹ K in the core) and jet-to-counterjet ratios consistent with only mildly relativistic intrinsic speeds (β ≲ 0.6 for inclinations θ ≲ 80°), indicating weakly powered pc-scale outflows. The low radio-Eddington ratios $\mathrm{log}({L}_{{\rm{R}}},1.4\,{\rm{GHz}}/{L}_{{\rm{Edd}}})\approx -5$ to -8 support this interpretation. Three objects lie on the fundamental plane of black hole activity, implying that global accretion-jet coupling in spiral DRAGNs is similar to that in other AGNs. Comparison with recent general relativistic magnetohydrodynamics simulations of thin-disk jets suggests that the VLBI-scale cores in spiral DRAGNs may trace an early or intermittently magnetized phase of jet launching. The coexistence of weak pc-scale jets and large kpc-scale lobes implies recurrent or long-duty-cycle jet activity in these late-type hosts.