Hs 129 barely flyable

[csThor]

Basically the Hs 129 was used like a flying anti-tank gun ... a basically defensive weapon. It wasn't used to intrude into soviet territory to hunt soviet tank formations but used to attack (and hopefully destroy) soviet tanks which were either attacking german positions or which had broken through into german-controlled territory.
It was, however, not used exclusively under fighter-cover (there were never enough german fighters to allow that). Rather the opposite was true as the VVS rarely ventured into german-controlled airspace until 1944 due to their fighter doctrine. They tied their fighters to specific targets - like a ground-target or a flight of own bombers/Il-2s they had to protect - instead of allowing them to roam freely like the german fighters were allowed to. Because of this Hs 129 did not encounter soviet fighters very often and mostly "by accident".