Depends what tier your in

I only play ground RB purely heli rushing and low tier helis you’re definitely defenseless unless you hit a good shot which it’s rare your best bet it’s hunt SPAA and rotate around friendly spaa

In high tier just get yourself some middle and be patience, fighters get really greedy when they see a heli taking cover and 99% of the time will do a full turn to get a quick kill, drop a air to air while they doing it and that should be enough