  An existence of the charge-induced instability is well known for the 4He
crystal surface in the rough state. Much less is known about charge-induced
instability at the 4He crystal surface in the smooth well-faceted state below
the roughening transition temperature. To meet the lack, we examine here the
latter case. As long as the electric field normal to the crystal facet is below
the critical value same as for the rough surface, the crystal faceting remains
absolutely stable. Above the critical field, unlike absolutely unstable state
of the rough surface, the crystal facet crosses over to the metastable state
separated from new crushed state with a potential barrier proportional to the
square of the linear facet step energy. The onset and development of the
instability at the charged crystal facet has much in common with the nucleation
kinetics of first-order phase transitions. Depending on the temperature, the
electric breaking strength is determined either by thermal activation at high
temperatures or by quantum tunneling at sufficiently low temperatures.
