The missed approach maneuver following an ILS approach to minima is frequent cause for a descent below the published minima...and yes it is indeed allowed, as the
decision to go-around is taken
at minima (or at least it
should be)...note that this is not allowed on non-precision approaches.
In older 707 aircraft, have actually just touched the main gear on go-around, such was the rather long spool-up time required with straight pipe engines.
